diff --git a/GPy/examples/__init__.py b/GPy/examples/__init__.py
index 87548553..c575bb33 100644
--- a/GPy/examples/__init__.py
+++ b/GPy/examples/__init__.py
@@ -6,4 +6,4 @@ import regression
 import dimensionality_reduction
 import tutorials
 import stochastic
-import non_gaussian
\ No newline at end of file
+import non_gaussian
diff --git a/GPy/examples/non_gaussian.py b/GPy/examples/non_gaussian.py
index cc87b360..c0fcd693 100644
--- a/GPy/examples/non_gaussian.py
+++ b/GPy/examples/non_gaussian.py
@@ -158,7 +158,7 @@ def boston_example(optimize=True, plot=True):
         #Gaussian GP
         print "Gauss GP"
         mgp = GPy.models.GPRegression(X_train.copy(), Y_train.copy(), kernel=kernelgp.copy())
-        mgp.constrain_fixed('white', 1e-5)
+        mgp.constrain_fixed('.*white', 1e-5)
         mgp['rbf_len'] = rbf_len
         mgp['noise'] = noise
         print mgp
@@ -176,7 +176,7 @@ def boston_example(optimize=True, plot=True):
         g_likelihood = GPy.likelihoods.Laplace(Y_train.copy(), g_distribution)
         mg = GPy.models.GPRegression(X_train.copy(), Y_train.copy(), kernel=kernelstu.copy(), likelihood=g_likelihood)
         mg.constrain_positive('noise_variance')
-        mg.constrain_fixed('white', 1e-5)
+        mg.constrain_fixed('.*white', 1e-5)
         mg['rbf_len'] = rbf_len
         mg['noise'] = noise
         print mg
@@ -194,10 +194,10 @@ def boston_example(optimize=True, plot=True):
             t_distribution = GPy.likelihoods.noise_model_constructors.student_t(deg_free=df, sigma2=noise)
             stu_t_likelihood = GPy.likelihoods.Laplace(Y_train.copy(), t_distribution)
             mstu_t = GPy.models.GPRegression(X_train.copy(), Y_train.copy(), kernel=kernelstu.copy(), likelihood=stu_t_likelihood)
-            mstu_t.constrain_fixed('white', 1e-5)
-            mstu_t.constrain_bounded('t_noise', 0.0001, 1000)
+            mstu_t.constrain_fixed('.*white', 1e-5)
+            mstu_t.constrain_bounded('.*t_noise', 0.0001, 1000)
             mstu_t['rbf_len'] = rbf_len
-            mstu_t['t_noise'] = noise
+            mstu_t['.*t_noise'] = noise
             print mstu_t
             if optimize:
                 mstu_t.optimize(optimizer=optimizer, messages=messages)
diff --git a/GPy/inference/latent_function_inference/laplace.py b/GPy/inference/latent_function_inference/laplace.py
index 4f529d5e..12315a29 100644
--- a/GPy/inference/latent_function_inference/laplace.py
+++ b/GPy/inference/latent_function_inference/laplace.py
@@ -51,12 +51,11 @@ class Laplace(object):
             Ki_f_init = self._previous_Ki_fhat
 
         f_hat, Ki_fhat = self.rasm_mode(K, Y, likelihood, Ki_f_init, Y_metadata=Y_metadata)
-
         self.f_hat = f_hat
         self.Ki_fhat =  Ki_fhat
         self.K = K.copy()
         #Compute hessian and other variables at mode
-        log_marginal, woodbury_vector, woodbury_inv, dL_dK, dL_dthetaL = self.mode_computations(f_hat, Ki_fhat, K, Y, likelihood, kern, Y_metadata)
+        log_marginal, woodbury_inv, dL_dK, dL_dthetaL = self.mode_computations(f_hat, Ki_fhat, K, Y, likelihood, kern, Y_metadata)
 
         self._previous_Ki_fhat = Ki_fhat.copy()
         return Posterior(woodbury_vector=Ki_fhat, woodbury_inv=woodbury_inv, K=K), log_marginal, {'dL_dK':dL_dK, 'dL_dthetaL':dL_dthetaL}
@@ -86,13 +85,13 @@ class Laplace(object):
 
         #define the objective function (to be maximised)
         def obj(Ki_f, f):
-            return -0.5*np.dot(Ki_f.flatten(), f.flatten()) + likelihood.logpdf(f, Y, extra_data=Y_metadata)
+            return -0.5*np.dot(Ki_f.flatten(), f.flatten()) + likelihood.logpdf(f, Y, Y_metadata=Y_metadata)
 
         difference = np.inf
         iteration = 0
         while difference > self._mode_finding_tolerance and iteration < self._mode_finding_max_iter:
-            W = -likelihood.d2logpdf_df2(f, Y, extra_data=Y_metadata)
-            grad = likelihood.dlogpdf_df(f, Y, extra_data=Y_metadata)
+            W = -likelihood.d2logpdf_df2(f, Y, Y_metadata=Y_metadata)
+            grad = likelihood.dlogpdf_df(f, Y, Y_metadata=Y_metadata)
 
             W_f = W*f
 
@@ -136,13 +135,12 @@ class Laplace(object):
         At the mode, compute the hessian and effective covariance matrix.
 
         returns: logZ : approximation to the marginal likelihood
-                 woodbury_vector : variable required for calculating the approximation to the covariance matrix
                  woodbury_inv : variable required for calculating the approximation to the covariance matrix
                  dL_dthetaL : array of derivatives (1 x num_kernel_params)
                  dL_dthetaL : array of derivatives (1 x num_likelihood_params)
         """
         #At this point get the hessian matrix (or vector as W is diagonal)
-        W = -likelihood.d2logpdf_df2(f_hat, Y, extra_data=Y_metadata)
+        W = -likelihood.d2logpdf_df2(f_hat, Y, Y_metadata=Y_metadata)
 
         K_Wi_i, L, LiW12 = self._compute_B_statistics(K, W, likelihood.log_concave)
 
@@ -151,11 +149,10 @@ class Laplace(object):
         Ki_W_i  = K - C.T.dot(C) #Could this be wrong?
 
         #compute the log marginal
-        log_marginal = -0.5*np.dot(Ki_f.flatten(), f_hat.flatten()) + likelihood.logpdf(f_hat, Y, extra_data=Y_metadata) - np.sum(np.log(np.diag(L)))
+        log_marginal = -0.5*np.dot(Ki_f.flatten(), f_hat.flatten()) + likelihood.logpdf(f_hat, Y, Y_metadata=Y_metadata) - np.sum(np.log(np.diag(L)))
 
         #Compute vival matrices for derivatives
-        dW_df = -likelihood.d3logpdf_df3(f_hat, Y, extra_data=Y_metadata) # -d3lik_d3fhat
-        woodbury_vector = likelihood.dlogpdf_df(f_hat, Y, extra_data=Y_metadata)
+        dW_df = -likelihood.d3logpdf_df3(f_hat, Y, Y_metadata=Y_metadata) # -d3lik_d3fhat
         dL_dfhat = -0.5*(np.diag(Ki_W_i)[:, None]*dW_df) #why isn't this -0.5? s2 in R&W p126 line 9.
         #BiK, _ = dpotrs(L, K, lower=1)
         #dL_dfhat = 0.5*np.diag(BiK)[:, None]*dW_df
@@ -169,7 +166,7 @@ class Laplace(object):
             explicit_part = 0.5*(np.dot(Ki_f, Ki_f.T) - K_Wi_i)
 
             #Implicit
-            implicit_part = np.dot(woodbury_vector, dL_dfhat.T).dot(I_KW_i)
+            implicit_part = np.dot(Ki_f, dL_dfhat.T).dot(I_KW_i)
 
             dL_dK = explicit_part + implicit_part
         else:
@@ -179,7 +176,7 @@ class Laplace(object):
         #compute dL_dthetaL#
         ####################
         if likelihood.size > 0 and not likelihood.is_fixed:
-            dlik_dthetaL, dlik_grad_dthetaL, dlik_hess_dthetaL = likelihood._laplace_gradients(f_hat, Y, extra_data=Y_metadata)
+            dlik_dthetaL, dlik_grad_dthetaL, dlik_hess_dthetaL = likelihood._laplace_gradients(f_hat, Y, Y_metadata=Y_metadata)
 
             num_params = likelihood.size
             # make space for one derivative for each likelihood parameter
@@ -200,7 +197,7 @@ class Laplace(object):
         else:
             dL_dthetaL = np.zeros(likelihood.size)
 
-        return log_marginal, woodbury_vector, K_Wi_i, dL_dK, dL_dthetaL
+        return log_marginal, K_Wi_i, dL_dK, dL_dthetaL
 
     def _compute_B_statistics(self, K, W, log_concave):
         """
diff --git a/GPy/likelihoods/bernoulli.py b/GPy/likelihoods/bernoulli.py
index 6c22e3d1..371fbe63 100644
--- a/GPy/likelihoods/bernoulli.py
+++ b/GPy/likelihoods/bernoulli.py
@@ -95,7 +95,7 @@ class Bernoulli(Likelihood):
         else:
             return np.nan
 
-    def pdf_link(self, link_f, y, extra_data=None):
+    def pdf_link(self, link_f, y, Y_metadata=None):
         """
         Likelihood function given link(f)
 
@@ -106,7 +106,7 @@ class Bernoulli(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data not used in bernoulli
+        :param Y_metadata: Y_metadata not used in bernoulli
         :returns: likelihood evaluated for this point
         :rtype: float
 
@@ -118,7 +118,7 @@ class Bernoulli(Likelihood):
         objective = np.where(y, link_f, 1.-link_f)
         return np.exp(np.sum(np.log(objective)))
 
-    def logpdf_link(self, link_f, y, extra_data=None):
+    def logpdf_link(self, link_f, y, Y_metadata=None):
         """
         Log Likelihood function given link(f)
 
@@ -129,7 +129,7 @@ class Bernoulli(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data not used in bernoulli
+        :param Y_metadata: Y_metadata not used in bernoulli
         :returns: log likelihood evaluated at points link(f)
         :rtype: float
         """
@@ -140,7 +140,7 @@ class Bernoulli(Likelihood):
         np.seterr(**state)
         return np.sum(objective)
 
-    def dlogpdf_dlink(self, link_f, y, extra_data=None):
+    def dlogpdf_dlink(self, link_f, y, Y_metadata=None):
         """
         Gradient of the pdf at y, given link(f) w.r.t link(f)
 
@@ -151,7 +151,7 @@ class Bernoulli(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data not used in bernoulli
+        :param Y_metadata: Y_metadata not used in bernoulli
         :returns: gradient of log likelihood evaluated at points link(f)
         :rtype: Nx1 array
         """
@@ -162,7 +162,7 @@ class Bernoulli(Likelihood):
         np.seterr(**state)
         return grad
 
-    def d2logpdf_dlink2(self, link_f, y, extra_data=None):
+    def d2logpdf_dlink2(self, link_f, y, Y_metadata=None):
         """
         Hessian at y, given link_f, w.r.t link_f the hessian will be 0 unless i == j
         i.e. second derivative logpdf at y given link(f_i) link(f_j)  w.r.t link(f_i) and link(f_j)
@@ -175,7 +175,7 @@ class Bernoulli(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data not used in bernoulli
+        :param Y_metadata: Y_metadata not used in bernoulli
         :returns: Diagonal of log hessian matrix (second derivative of log likelihood evaluated at points link(f))
         :rtype: Nx1 array
 
@@ -190,7 +190,7 @@ class Bernoulli(Likelihood):
         np.seterr(**state)
         return d2logpdf_dlink2
 
-    def d3logpdf_dlink3(self, link_f, y, extra_data=None):
+    def d3logpdf_dlink3(self, link_f, y, Y_metadata=None):
         """
         Third order derivative log-likelihood function at y given link(f) w.r.t link(f)
 
@@ -201,7 +201,7 @@ class Bernoulli(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data not used in bernoulli
+        :param Y_metadata: Y_metadata not used in bernoulli
         :returns: third derivative of log likelihood evaluated at points link(f)
         :rtype: Nx1 array
         """
diff --git a/GPy/likelihoods/exponential.py b/GPy/likelihoods/exponential.py
index 8d2e8cdc..1dd548f6 100644
--- a/GPy/likelihoods/exponential.py
+++ b/GPy/likelihoods/exponential.py
@@ -18,13 +18,12 @@ class Exponential(Likelihood):
     L(x) = \exp(\lambda) * \lambda**Y_i / Y_i!
     $$
     """
-    def __init__(self,gp_link=None,analytical_mean=False,analytical_variance=False):
-        super(Exponential, self).__init__(gp_link,analytical_mean,analytical_variance)
+    def __init__(self,gp_link=None):
+        if gp_link is None:
+            gp_link = link_functions.Log()
+        super(Exponential, self).__init__(gp_link, 'ExpLikelihood')
 
-    def _preprocess_values(self,Y):
-        return Y
-
-    def pdf_link(self, link_f, y, extra_data=None):
+    def pdf_link(self, link_f, y, Y_metadata=None):
         """
         Likelihood function given link(f)
 
@@ -35,16 +34,15 @@ class Exponential(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in exponential distribution
+        :param Y_metadata: Y_metadata which is not used in exponential distribution
         :returns: likelihood evaluated for this point
         :rtype: float
         """
         assert np.atleast_1d(link_f).shape == np.atleast_1d(y).shape
         log_objective = link_f*np.exp(-y*link_f)
         return np.exp(np.sum(np.log(log_objective)))
-        #return np.exp(np.sum(-y/link_f - np.log(link_f) ))
 
-    def logpdf_link(self, link_f, y, extra_data=None):
+    def logpdf_link(self, link_f, y, Y_metadata=None):
         """
         Log Likelihood Function given link(f)
 
@@ -55,17 +53,16 @@ class Exponential(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in exponential distribution
+        :param Y_metadata: Y_metadata which is not used in exponential distribution
         :returns: likelihood evaluated for this point
         :rtype: float
 
         """
         assert np.atleast_1d(link_f).shape == np.atleast_1d(y).shape
         log_objective = np.log(link_f) - y*link_f
-        #logpdf_link = np.sum(-np.log(link_f) - y/link_f)
         return np.sum(log_objective)
 
-    def dlogpdf_dlink(self, link_f, y, extra_data=None):
+    def dlogpdf_dlink(self, link_f, y, Y_metadata=None):
         """
         Gradient of the log likelihood function at y, given link(f) w.r.t link(f)
 
@@ -76,7 +73,7 @@ class Exponential(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in exponential distribution
+        :param Y_metadata: Y_metadata which is not used in exponential distribution
         :returns: gradient of likelihood evaluated at points
         :rtype: Nx1 array
 
@@ -86,7 +83,7 @@ class Exponential(Likelihood):
         #grad = y/(link_f**2) - 1./link_f
         return grad
 
-    def d2logpdf_dlink2(self, link_f, y, extra_data=None):
+    def d2logpdf_dlink2(self, link_f, y, Y_metadata=None):
         """
         Hessian at y, given link(f), w.r.t link(f)
         i.e. second derivative logpdf at y given link(f_i) and link(f_j)  w.r.t link(f_i) and link(f_j)
@@ -99,7 +96,7 @@ class Exponential(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in exponential distribution
+        :param Y_metadata: Y_metadata which is not used in exponential distribution
         :returns: Diagonal of hessian matrix (second derivative of likelihood evaluated at points f)
         :rtype: Nx1 array
 
@@ -112,7 +109,7 @@ class Exponential(Likelihood):
         #hess = -2*y/(link_f**3) + 1/(link_f**2)
         return hess
 
-    def d3logpdf_dlink3(self, link_f, y, extra_data=None):
+    def d3logpdf_dlink3(self, link_f, y, Y_metadata=None):
         """
         Third order derivative log-likelihood function at y given link(f) w.r.t link(f)
 
@@ -123,7 +120,7 @@ class Exponential(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in exponential distribution
+        :param Y_metadata: Y_metadata which is not used in exponential distribution
         :returns: third derivative of likelihood evaluated at points f
         :rtype: Nx1 array
         """
@@ -132,18 +129,6 @@ class Exponential(Likelihood):
         #d3lik_dlink3 = 6*y/(link_f**4) - 2./(link_f**3)
         return d3lik_dlink3
 
-    def _mean(self,gp):
-        """
-        Mass (or density) function
-        """
-        return self.gp_link.transf(gp)
-
-    def _variance(self,gp):
-        """
-        Mass (or density) function
-        """
-        return self.gp_link.transf(gp)**2
-
     def samples(self, gp):
         """
         Returns a set of samples of observations based on a given value of the latent variable.
diff --git a/GPy/likelihoods/gamma.py b/GPy/likelihoods/gamma.py
index 0ac70a9f..a6436616 100644
--- a/GPy/likelihoods/gamma.py
+++ b/GPy/likelihoods/gamma.py
@@ -1,11 +1,12 @@
-# Copyright (c) 2012, 2013 Ricardo Andrade
+# Copyright (c) 2012 - 2014, GPy authors (see AUTHORS.txt).
 # Licensed under the BSD 3-clause license (see LICENSE.txt)
 
 
 import numpy as np
 from scipy import stats,special
 import scipy as sp
-from GPy.util.univariate_Gaussian import std_norm_pdf,std_norm_cdf
+from ..util.univariate_Gaussian import std_norm_pdf,std_norm_cdf
+from ..core.parameterization import Param
 import link_functions
 from likelihood import Likelihood
 
@@ -18,14 +19,16 @@ class Gamma(Likelihood):
         \\alpha_{i} = \\beta y_{i}
 
     """
-    def __init__(self,gp_link=None,analytical_mean=False,analytical_variance=False,beta=1.):
-        self.beta = beta
-        super(Gamma, self).__init__(gp_link,analytical_mean,analytical_variance)
+    def __init__(self,gp_link=None,beta=1.):
+        if gp_link is None:
+            gp_link = link_functions.Log()
+        super(Gamma, self).__init__(gp_link, 'Gamma')
 
-    def _preprocess_values(self,Y):
-        return Y
+        self.beta = Param('beta', beta)
+        self.add_parameter(self.beta)
+        self.beta.fix()#TODO: gradients!
 
-    def pdf_link(self, link_f, y, extra_data=None):
+    def pdf_link(self, link_f, y, Y_metadata=None):
         """
         Likelihood function given link(f)
 
@@ -37,7 +40,7 @@ class Gamma(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in poisson distribution
+        :param Y_metadata: Y_metadata which is not used in poisson distribution
         :returns: likelihood evaluated for this point
         :rtype: float
         """
@@ -47,7 +50,7 @@ class Gamma(Likelihood):
         objective = (y**(alpha - 1.) * np.exp(-self.beta*y) * self.beta**alpha)/ special.gamma(alpha)
         return np.exp(np.sum(np.log(objective)))
 
-    def logpdf_link(self, link_f, y, extra_data=None):
+    def logpdf_link(self, link_f, y, Y_metadata=None):
         """
         Log Likelihood Function given link(f)
 
@@ -59,7 +62,7 @@ class Gamma(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in poisson distribution
+        :param Y_metadata: Y_metadata which is not used in poisson distribution
         :returns: likelihood evaluated for this point
         :rtype: float
 
@@ -71,7 +74,7 @@ class Gamma(Likelihood):
         log_objective = alpha*np.log(self.beta) - np.log(special.gamma(alpha)) + (alpha - 1)*np.log(y) - self.beta*y
         return np.sum(log_objective)
 
-    def dlogpdf_dlink(self, link_f, y, extra_data=None):
+    def dlogpdf_dlink(self, link_f, y, Y_metadata=None):
         """
         Gradient of the log likelihood function at y, given link(f) w.r.t link(f)
 
@@ -83,7 +86,7 @@ class Gamma(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in gamma distribution
+        :param Y_metadata: Y_metadata which is not used in gamma distribution
         :returns: gradient of likelihood evaluated at points
         :rtype: Nx1 array
 
@@ -94,7 +97,7 @@ class Gamma(Likelihood):
         #return -self.gp_link.dtransf_df(gp)*self.beta*np.log(obs) + special.psi(self.gp_link.transf(gp)*self.beta) * self.gp_link.dtransf_df(gp)*self.beta
         return grad
 
-    def d2logpdf_dlink2(self, link_f, y, extra_data=None):
+    def d2logpdf_dlink2(self, link_f, y, Y_metadata=None):
         """
         Hessian at y, given link(f), w.r.t link(f)
         i.e. second derivative logpdf at y given link(f_i) and link(f_j)  w.r.t link(f_i) and link(f_j)
@@ -108,7 +111,7 @@ class Gamma(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in gamma distribution
+        :param Y_metadata: Y_metadata which is not used in gamma distribution
         :returns: Diagonal of hessian matrix (second derivative of likelihood evaluated at points f)
         :rtype: Nx1 array
 
@@ -122,7 +125,7 @@ class Gamma(Likelihood):
         #return -self.gp_link.d2transf_df2(gp)*self.beta*np.log(obs) + special.polygamma(1,self.gp_link.transf(gp)*self.beta)*(self.gp_link.dtransf_df(gp)*self.beta)**2 + special.psi(self.gp_link.transf(gp)*self.beta)*self.gp_link.d2transf_df2(gp)*self.beta
         return hess
 
-    def d3logpdf_dlink3(self, link_f, y, extra_data=None):
+    def d3logpdf_dlink3(self, link_f, y, Y_metadata=None):
         """
         Third order derivative log-likelihood function at y given link(f) w.r.t link(f)
 
@@ -134,22 +137,10 @@ class Gamma(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in gamma distribution
+        :param Y_metadata: Y_metadata which is not used in gamma distribution
         :returns: third derivative of likelihood evaluated at points f
         :rtype: Nx1 array
         """
         assert np.atleast_1d(link_f).shape == np.atleast_1d(y).shape
         d3lik_dlink3 = -special.polygamma(2, self.beta*link_f)*(self.beta**3)
         return d3lik_dlink3
-
-    def _mean(self,gp):
-        """
-        Mass (or density) function
-        """
-        return self.gp_link.transf(gp)
-
-    def _variance(self,gp):
-        """
-        Mass (or density) function
-        """
-        return self.gp_link.transf(gp)/self.beta
diff --git a/GPy/likelihoods/gaussian.py b/GPy/likelihoods/gaussian.py
index 89ad4486..6534f0ca 100644
--- a/GPy/likelihoods/gaussian.py
+++ b/GPy/likelihoods/gaussian.py
@@ -97,10 +97,14 @@ class Gaussian(Likelihood):
     def predictive_variance(self, mu, sigma, predictive_mean=None):
         return self.variance + sigma**2
 
+<<<<<<< HEAD
+    def pdf_link(self, link_f, y, Y_metadata=None):
+=======
     def predictive_quantiles(self, mu, var, quantiles, Y_metadata):
         return  [stats.norm.ppf(q/100.)*np.sqrt(var) + mu for q in quantiles]
 
     def pdf_link(self, link_f, y, extra_data=None):
+>>>>>>> a3287c38ea775155df4e90f7fe1883d12ffb54b9
         """
         Likelihood function given link(f)
 
@@ -111,14 +115,14 @@ class Gaussian(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data not used in gaussian
+        :param Y_metadata: Y_metadata not used in gaussian
         :returns: likelihood evaluated for this point
         :rtype: float
         """
         #Assumes no covariance, exp, sum, log for numerical stability
         return np.exp(np.sum(np.log(stats.norm.pdf(y, link_f, np.sqrt(self.variance)))))
 
-    def logpdf_link(self, link_f, y, extra_data=None):
+    def logpdf_link(self, link_f, y, Y_metadata=None):
         """
         Log likelihood function given link(f)
 
@@ -129,7 +133,7 @@ class Gaussian(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data not used in gaussian
+        :param Y_metadata: Y_metadata not used in gaussian
         :returns: log likelihood evaluated for this point
         :rtype: float
         """
@@ -139,7 +143,7 @@ class Gaussian(Likelihood):
 
         return -0.5*(np.sum((y-link_f)**2/self.variance) + ln_det_cov + N*np.log(2.*np.pi))
 
-    def dlogpdf_dlink(self, link_f, y, extra_data=None):
+    def dlogpdf_dlink(self, link_f, y, Y_metadata=None):
         """
         Gradient of the pdf at y, given link(f) w.r.t link(f)
 
@@ -150,7 +154,7 @@ class Gaussian(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data not used in gaussian
+        :param Y_metadata: Y_metadata not used in gaussian
         :returns: gradient of log likelihood evaluated at points link(f)
         :rtype: Nx1 array
         """
@@ -159,7 +163,7 @@ class Gaussian(Likelihood):
         grad = s2_i*y - s2_i*link_f
         return grad
 
-    def d2logpdf_dlink2(self, link_f, y, extra_data=None):
+    def d2logpdf_dlink2(self, link_f, y, Y_metadata=None):
         """
         Hessian at y, given link_f, w.r.t link_f.
         i.e. second derivative logpdf at y given link(f_i) link(f_j)  w.r.t link(f_i) and link(f_j)
@@ -173,7 +177,7 @@ class Gaussian(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data not used in gaussian
+        :param Y_metadata: Y_metadata not used in gaussian
         :returns: Diagonal of log hessian matrix (second derivative of log likelihood evaluated at points link(f))
         :rtype: Nx1 array
 
@@ -186,7 +190,7 @@ class Gaussian(Likelihood):
         hess = -(1.0/self.variance)*np.ones((N, 1))
         return hess
 
-    def d3logpdf_dlink3(self, link_f, y, extra_data=None):
+    def d3logpdf_dlink3(self, link_f, y, Y_metadata=None):
         """
         Third order derivative log-likelihood function at y given link(f) w.r.t link(f)
 
@@ -197,7 +201,7 @@ class Gaussian(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data not used in gaussian
+        :param Y_metadata: Y_metadata not used in gaussian
         :returns: third derivative of log likelihood evaluated at points link(f)
         :rtype: Nx1 array
         """
@@ -206,7 +210,7 @@ class Gaussian(Likelihood):
         d3logpdf_dlink3 = np.zeros((N,1))
         return d3logpdf_dlink3
 
-    def dlogpdf_link_dvar(self, link_f, y, extra_data=None):
+    def dlogpdf_link_dvar(self, link_f, y, Y_metadata=None):
         """
         Gradient of the log-likelihood function at y given link(f), w.r.t variance parameter (noise_variance)
 
@@ -217,7 +221,7 @@ class Gaussian(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data not used in gaussian
+        :param Y_metadata: Y_metadata not used in gaussian
         :returns: derivative of log likelihood evaluated at points link(f) w.r.t variance parameter
         :rtype: float
         """
@@ -228,7 +232,7 @@ class Gaussian(Likelihood):
         dlik_dsigma = -0.5*N/self.variance + 0.5*s_4*np.sum(np.square(e))
         return np.sum(dlik_dsigma) # Sure about this sum?
 
-    def dlogpdf_dlink_dvar(self, link_f, y, extra_data=None):
+    def dlogpdf_dlink_dvar(self, link_f, y, Y_metadata=None):
         """
         Derivative of the dlogpdf_dlink w.r.t variance parameter (noise_variance)
 
@@ -239,7 +243,7 @@ class Gaussian(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data not used in gaussian
+        :param Y_metadata: Y_metadata not used in gaussian
         :returns: derivative of log likelihood evaluated at points link(f) w.r.t variance parameter
         :rtype: Nx1 array
         """
@@ -248,7 +252,7 @@ class Gaussian(Likelihood):
         dlik_grad_dsigma = -s_4*y + s_4*link_f
         return dlik_grad_dsigma
 
-    def d2logpdf_dlink2_dvar(self, link_f, y, extra_data=None):
+    def d2logpdf_dlink2_dvar(self, link_f, y, Y_metadata=None):
         """
         Gradient of the hessian (d2logpdf_dlink2) w.r.t variance parameter (noise_variance)
 
@@ -259,7 +263,7 @@ class Gaussian(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data not used in gaussian
+        :param Y_metadata: Y_metadata not used in gaussian
         :returns: derivative of log hessian evaluated at points link(f_i) and link(f_j) w.r.t variance parameter
         :rtype: Nx1 array
         """
@@ -269,16 +273,16 @@ class Gaussian(Likelihood):
         d2logpdf_dlink2_dvar = np.ones((N,1))*s_4
         return d2logpdf_dlink2_dvar
 
-    def dlogpdf_link_dtheta(self, f, y, extra_data=None):
-        dlogpdf_dvar = self.dlogpdf_link_dvar(f, y, extra_data=extra_data)
+    def dlogpdf_link_dtheta(self, f, y, Y_metadata=None):
+        dlogpdf_dvar = self.dlogpdf_link_dvar(f, y, Y_metadata=Y_metadata)
         return np.asarray([[dlogpdf_dvar]])
 
-    def dlogpdf_dlink_dtheta(self, f, y, extra_data=None):
-        dlogpdf_dlink_dvar = self.dlogpdf_dlink_dvar(f, y, extra_data=extra_data)
+    def dlogpdf_dlink_dtheta(self, f, y, Y_metadata=None):
+        dlogpdf_dlink_dvar = self.dlogpdf_dlink_dvar(f, y, Y_metadata=Y_metadata)
         return dlogpdf_dlink_dvar
 
-    def d2logpdf_dlink2_dtheta(self, f, y, extra_data=None):
-        d2logpdf_dlink2_dvar = self.d2logpdf_dlink2_dvar(f, y, extra_data=extra_data)
+    def d2logpdf_dlink2_dtheta(self, f, y, Y_metadata=None):
+        d2logpdf_dlink2_dvar = self.d2logpdf_dlink2_dvar(f, y, Y_metadata=Y_metadata)
         return d2logpdf_dlink2_dvar
 
     def _mean(self, gp):
diff --git a/GPy/likelihoods/likelihood.py b/GPy/likelihoods/likelihood.py
index e7bad74a..6df573df 100644
--- a/GPy/likelihoods/likelihood.py
+++ b/GPy/likelihoods/likelihood.py
@@ -153,6 +153,10 @@ class Likelihood(Parameterized):
 
         return mean
 
+    def _conditional_mean(self, f):
+        """Quadrature calculation of the conditional mean: E(Y_star|f)"""
+        raise NotImplementedError, "implement this function to make predictions"
+
     def predictive_variance(self, mu,variance, predictive_mean=None, Y_metadata=None):
         """
         Numerical approximation to the predictive variance: V(Y_star)
@@ -204,31 +208,31 @@ class Likelihood(Parameterized):
         # V(Y_star) = E[ V(Y_star|f_star) ] + E(Y_star**2|f_star) - E[Y_star|f_star]**2
         return exp_var + var_exp
 
-    def pdf_link(self, link_f, y, extra_data=None):
+    def pdf_link(self, link_f, y, Y_metadata=None):
         raise NotImplementedError
 
-    def logpdf_link(self, link_f, y, extra_data=None):
+    def logpdf_link(self, link_f, y, Y_metadata=None):
         raise NotImplementedError
 
-    def dlogpdf_dlink(self, link_f, y, extra_data=None):
+    def dlogpdf_dlink(self, link_f, y, Y_metadata=None):
         raise NotImplementedError
 
-    def d2logpdf_dlink2(self, link_f, y, extra_data=None):
+    def d2logpdf_dlink2(self, link_f, y, Y_metadata=None):
         raise NotImplementedError
 
-    def d3logpdf_dlink3(self, link_f, y, extra_data=None):
+    def d3logpdf_dlink3(self, link_f, y, Y_metadata=None):
         raise NotImplementedError
 
-    def dlogpdf_link_dtheta(self, link_f, y, extra_data=None):
+    def dlogpdf_link_dtheta(self, link_f, y, Y_metadata=None):
         raise NotImplementedError
 
-    def dlogpdf_dlink_dtheta(self, link_f, y, extra_data=None):
+    def dlogpdf_dlink_dtheta(self, link_f, y, Y_metadata=None):
         raise NotImplementedError
 
-    def d2logpdf_dlink2_dtheta(self, link_f, y, extra_data=None):
+    def d2logpdf_dlink2_dtheta(self, link_f, y, Y_metadata=None):
         raise NotImplementedError
 
-    def pdf(self, f, y, extra_data=None):
+    def pdf(self, f, y, Y_metadata=None):
         """
         Evaluates the link function link(f) then computes the likelihood (pdf) using it
 
@@ -239,14 +243,14 @@ class Likelihood(Parameterized):
         :type f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in student t distribution - not used
+        :param Y_metadata: Y_metadata which is not used in student t distribution - not used
         :returns: likelihood evaluated for this point
         :rtype: float
         """
         link_f = self.gp_link.transf(f)
-        return self.pdf_link(link_f, y, extra_data=extra_data)
+        return self.pdf_link(link_f, y, Y_metadata=Y_metadata)
 
-    def logpdf(self, f, y, extra_data=None):
+    def logpdf(self, f, y, Y_metadata=None):
         """
         Evaluates the link function link(f) then computes the log likelihood (log pdf) using it
 
@@ -257,14 +261,14 @@ class Likelihood(Parameterized):
         :type f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in student t distribution - not used
+        :param Y_metadata: Y_metadata which is not used in student t distribution - not used
         :returns: log likelihood evaluated for this point
         :rtype: float
         """
         link_f = self.gp_link.transf(f)
-        return self.logpdf_link(link_f, y, extra_data=extra_data)
+        return self.logpdf_link(link_f, y, Y_metadata=Y_metadata)
 
-    def dlogpdf_df(self, f, y, extra_data=None):
+    def dlogpdf_df(self, f, y, Y_metadata=None):
         """
         Evaluates the link function link(f) then computes the derivative of log likelihood using it
         Uses the Faa di Bruno's formula for the chain rule
@@ -276,16 +280,16 @@ class Likelihood(Parameterized):
         :type f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in student t distribution - not used
+        :param Y_metadata: Y_metadata which is not used in student t distribution - not used
         :returns: derivative of log likelihood evaluated for this point
         :rtype: 1xN array
         """
         link_f = self.gp_link.transf(f)
-        dlogpdf_dlink = self.dlogpdf_dlink(link_f, y, extra_data=extra_data)
+        dlogpdf_dlink = self.dlogpdf_dlink(link_f, y, Y_metadata=Y_metadata)
         dlink_df = self.gp_link.dtransf_df(f)
         return chain_1(dlogpdf_dlink, dlink_df)
 
-    def d2logpdf_df2(self, f, y, extra_data=None):
+    def d2logpdf_df2(self, f, y, Y_metadata=None):
         """
         Evaluates the link function link(f) then computes the second derivative of log likelihood using it
         Uses the Faa di Bruno's formula for the chain rule
@@ -297,18 +301,18 @@ class Likelihood(Parameterized):
         :type f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in student t distribution - not used
+        :param Y_metadata: Y_metadata which is not used in student t distribution - not used
         :returns: second derivative of log likelihood evaluated for this point (diagonal only)
         :rtype: 1xN array
         """
         link_f = self.gp_link.transf(f)
-        d2logpdf_dlink2 = self.d2logpdf_dlink2(link_f, y, extra_data=extra_data)
+        d2logpdf_dlink2 = self.d2logpdf_dlink2(link_f, y, Y_metadata=Y_metadata)
         dlink_df = self.gp_link.dtransf_df(f)
-        dlogpdf_dlink = self.dlogpdf_dlink(link_f, y, extra_data=extra_data)
+        dlogpdf_dlink = self.dlogpdf_dlink(link_f, y, Y_metadata=Y_metadata)
         d2link_df2 = self.gp_link.d2transf_df2(f)
         return chain_2(d2logpdf_dlink2, dlink_df, dlogpdf_dlink, d2link_df2)
 
-    def d3logpdf_df3(self, f, y, extra_data=None):
+    def d3logpdf_df3(self, f, y, Y_metadata=None):
         """
         Evaluates the link function link(f) then computes the third derivative of log likelihood using it
         Uses the Faa di Bruno's formula for the chain rule
@@ -320,44 +324,44 @@ class Likelihood(Parameterized):
         :type f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in student t distribution - not used
+        :param Y_metadata: Y_metadata which is not used in student t distribution - not used
         :returns: third derivative of log likelihood evaluated for this point
         :rtype: float
         """
         link_f = self.gp_link.transf(f)
-        d3logpdf_dlink3 = self.d3logpdf_dlink3(link_f, y, extra_data=extra_data)
+        d3logpdf_dlink3 = self.d3logpdf_dlink3(link_f, y, Y_metadata=Y_metadata)
         dlink_df = self.gp_link.dtransf_df(f)
-        d2logpdf_dlink2 = self.d2logpdf_dlink2(link_f, y, extra_data=extra_data)
+        d2logpdf_dlink2 = self.d2logpdf_dlink2(link_f, y, Y_metadata=Y_metadata)
         d2link_df2 = self.gp_link.d2transf_df2(f)
-        dlogpdf_dlink = self.dlogpdf_dlink(link_f, y, extra_data=extra_data)
+        dlogpdf_dlink = self.dlogpdf_dlink(link_f, y, Y_metadata=Y_metadata)
         d3link_df3 = self.gp_link.d3transf_df3(f)
         return chain_3(d3logpdf_dlink3, dlink_df, d2logpdf_dlink2, d2link_df2, dlogpdf_dlink, d3link_df3)
 
-    def dlogpdf_dtheta(self, f, y, extra_data=None):
+    def dlogpdf_dtheta(self, f, y, Y_metadata=None):
         """
         TODO: Doc strings
         """
         if self.size > 0:
             link_f = self.gp_link.transf(f)
-            return self.dlogpdf_link_dtheta(link_f, y, extra_data=extra_data)
+            return self.dlogpdf_link_dtheta(link_f, y, Y_metadata=Y_metadata)
         else:
             #Is no parameters so return an empty array for its derivatives
             return np.zeros([1, 0])
 
-    def dlogpdf_df_dtheta(self, f, y, extra_data=None):
+    def dlogpdf_df_dtheta(self, f, y, Y_metadata=None):
         """
         TODO: Doc strings
         """
         if self.size > 0:
             link_f = self.gp_link.transf(f)
             dlink_df = self.gp_link.dtransf_df(f)
-            dlogpdf_dlink_dtheta = self.dlogpdf_dlink_dtheta(link_f, y, extra_data=extra_data)
+            dlogpdf_dlink_dtheta = self.dlogpdf_dlink_dtheta(link_f, y, Y_metadata=Y_metadata)
             return chain_1(dlogpdf_dlink_dtheta, dlink_df)
         else:
             #Is no parameters so return an empty array for its derivatives
             return np.zeros([f.shape[0], 0])
 
-    def d2logpdf_df2_dtheta(self, f, y, extra_data=None):
+    def d2logpdf_df2_dtheta(self, f, y, Y_metadata=None):
         """
         TODO: Doc strings
         """
@@ -365,17 +369,17 @@ class Likelihood(Parameterized):
             link_f = self.gp_link.transf(f)
             dlink_df = self.gp_link.dtransf_df(f)
             d2link_df2 = self.gp_link.d2transf_df2(f)
-            d2logpdf_dlink2_dtheta = self.d2logpdf_dlink2_dtheta(link_f, y, extra_data=extra_data)
-            dlogpdf_dlink_dtheta = self.dlogpdf_dlink_dtheta(link_f, y, extra_data=extra_data)
+            d2logpdf_dlink2_dtheta = self.d2logpdf_dlink2_dtheta(link_f, y, Y_metadata=Y_metadata)
+            dlogpdf_dlink_dtheta = self.dlogpdf_dlink_dtheta(link_f, y, Y_metadata=Y_metadata)
             return chain_2(d2logpdf_dlink2_dtheta, dlink_df, dlogpdf_dlink_dtheta, d2link_df2)
         else:
             #Is no parameters so return an empty array for its derivatives
             return np.zeros([f.shape[0], 0])
 
-    def _laplace_gradients(self, f, y, extra_data=None):
-        dlogpdf_dtheta = self.dlogpdf_dtheta(f, y, extra_data=extra_data)
-        dlogpdf_df_dtheta = self.dlogpdf_df_dtheta(f, y, extra_data=extra_data)
-        d2logpdf_df2_dtheta = self.d2logpdf_df2_dtheta(f, y, extra_data=extra_data)
+    def _laplace_gradients(self, f, y, Y_metadata=None):
+        dlogpdf_dtheta = self.dlogpdf_dtheta(f, y, Y_metadata=Y_metadata)
+        dlogpdf_df_dtheta = self.dlogpdf_df_dtheta(f, y, Y_metadata=Y_metadata)
+        d2logpdf_df2_dtheta = self.d2logpdf_df2_dtheta(f, y, Y_metadata=Y_metadata)
 
         #Parameters are stacked vertically. Must be listed in same order as 'get_param_names'
         # ensure we have gradients for every parameter we want to optimize
@@ -390,7 +394,7 @@ class Likelihood(Parameterized):
 
     def predictive_values(self, mu, var, full_cov=False, Y_metadata=None):
         """
-        Compute  mean, variance and conficence interval (percentiles 5 and 95) of the  prediction.
+        Compute  mean, variance of the  predictive distibution.
 
         :param mu: mean of the latent variable, f, of posterior
         :param var: variance of the latent variable, f, of posterior
diff --git a/GPy/likelihoods/poisson.py b/GPy/likelihoods/poisson.py
index c0e2c81f..862f873f 100644
--- a/GPy/likelihoods/poisson.py
+++ b/GPy/likelihoods/poisson.py
@@ -25,10 +25,13 @@ class Poisson(Likelihood):
 
         super(Poisson, self).__init__(gp_link, name='Poisson')
 
-    def _preprocess_values(self,Y):
-        return Y
+    def _conditional_mean(self, f):
+        """
+        the expected value of y given a value of f
+        """
+        return self.gp_link.transf(gp)
 
-    def pdf_link(self, link_f, y, extra_data=None):
+    def pdf_link(self, link_f, y, Y_metadata=None):
         """
         Likelihood function given link(f)
 
@@ -39,14 +42,14 @@ class Poisson(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in poisson distribution
+        :param Y_metadata: Y_metadata which is not used in poisson distribution
         :returns: likelihood evaluated for this point
         :rtype: float
         """
         assert np.atleast_1d(link_f).shape == np.atleast_1d(y).shape
         return np.prod(stats.poisson.pmf(y,link_f))
 
-    def logpdf_link(self, link_f, y, extra_data=None):
+    def logpdf_link(self, link_f, y, Y_metadata=None):
         """
         Log Likelihood Function given link(f)
 
@@ -57,7 +60,7 @@ class Poisson(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in poisson distribution
+        :param Y_metadata: Y_metadata which is not used in poisson distribution
         :returns: likelihood evaluated for this point
         :rtype: float
 
@@ -65,7 +68,7 @@ class Poisson(Likelihood):
         assert np.atleast_1d(link_f).shape == np.atleast_1d(y).shape
         return np.sum(-link_f + y*np.log(link_f) - special.gammaln(y+1))
 
-    def dlogpdf_dlink(self, link_f, y, extra_data=None):
+    def dlogpdf_dlink(self, link_f, y, Y_metadata=None):
         """
         Gradient of the log likelihood function at y, given link(f) w.r.t link(f)
 
@@ -76,7 +79,7 @@ class Poisson(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in poisson distribution
+        :param Y_metadata: Y_metadata which is not used in poisson distribution
         :returns: gradient of likelihood evaluated at points
         :rtype: Nx1 array
 
@@ -84,7 +87,7 @@ class Poisson(Likelihood):
         assert np.atleast_1d(link_f).shape == np.atleast_1d(y).shape
         return y/link_f - 1
 
-    def d2logpdf_dlink2(self, link_f, y, extra_data=None):
+    def d2logpdf_dlink2(self, link_f, y, Y_metadata=None):
         """
         Hessian at y, given link(f), w.r.t link(f)
         i.e. second derivative logpdf at y given link(f_i) and link(f_j)  w.r.t link(f_i) and link(f_j)
@@ -97,7 +100,7 @@ class Poisson(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in poisson distribution
+        :param Y_metadata: Y_metadata which is not used in poisson distribution
         :returns: Diagonal of hessian matrix (second derivative of likelihood evaluated at points f)
         :rtype: Nx1 array
 
@@ -112,7 +115,7 @@ class Poisson(Likelihood):
         #transf = self.gp_link.transf(gp)
         #return obs * ((self.gp_link.dtransf_df(gp)/transf)**2 - d2_df/transf) + d2_df
 
-    def d3logpdf_dlink3(self, link_f, y, extra_data=None):
+    def d3logpdf_dlink3(self, link_f, y, Y_metadata=None):
         """
         Third order derivative log-likelihood function at y given link(f) w.r.t link(f)
 
@@ -123,7 +126,7 @@ class Poisson(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in poisson distribution
+        :param Y_metadata: Y_metadata which is not used in poisson distribution
         :returns: third derivative of likelihood evaluated at points f
         :rtype: Nx1 array
         """
diff --git a/GPy/likelihoods/student_t.py b/GPy/likelihoods/student_t.py
index 15fd9fa0..6bb14207 100644
--- a/GPy/likelihoods/student_t.py
+++ b/GPy/likelihoods/student_t.py
@@ -43,10 +43,10 @@ class StudentT(Likelihood):
         Pull out the gradients, be careful as the order must match the order
         in which the parameters are added
         """
-        self.sigma2.gradient = grads[0]
-        self.v.gradient = grads[1]
+        self.sigma2.gradient = derivatives[0]
+        self.v.gradient = derivatives[1]
 
-    def pdf_link(self, link_f, y, extra_data=None):
+    def pdf_link(self, link_f, y, Y_metadata=None):
         """
         Likelihood function given link(f)
 
@@ -57,7 +57,7 @@ class StudentT(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in student t distribution
+        :param Y_metadata: Y_metadata which is not used in student t distribution
         :returns: likelihood evaluated for this point
         :rtype: float
         """
@@ -70,7 +70,7 @@ class StudentT(Likelihood):
                     )
         return np.prod(objective)
 
-    def logpdf_link(self, link_f, y, extra_data=None):
+    def logpdf_link(self, link_f, y, Y_metadata=None):
         """
         Log Likelihood Function given link(f)
 
@@ -81,7 +81,7 @@ class StudentT(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in student t distribution
+        :param Y_metadata: Y_metadata which is not used in student t distribution
         :returns: likelihood evaluated for this point
         :rtype: float
 
@@ -99,7 +99,7 @@ class StudentT(Likelihood):
                     )
         return np.sum(objective)
 
-    def dlogpdf_dlink(self, link_f, y, extra_data=None):
+    def dlogpdf_dlink(self, link_f, y, Y_metadata=None):
         """
         Gradient of the log likelihood function at y, given link(f) w.r.t link(f)
 
@@ -110,7 +110,7 @@ class StudentT(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in student t distribution
+        :param Y_metadata: Y_metadata which is not used in student t distribution
         :returns: gradient of likelihood evaluated at points
         :rtype: Nx1 array
 
@@ -120,7 +120,7 @@ class StudentT(Likelihood):
         grad = ((self.v + 1) * e) / (self.v * self.sigma2 + (e**2))
         return grad
 
-    def d2logpdf_dlink2(self, link_f, y, extra_data=None):
+    def d2logpdf_dlink2(self, link_f, y, Y_metadata=None):
         """
         Hessian at y, given link(f), w.r.t link(f)
         i.e. second derivative logpdf at y given link(f_i) and link(f_j)  w.r.t link(f_i) and link(f_j)
@@ -133,7 +133,7 @@ class StudentT(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in student t distribution
+        :param Y_metadata: Y_metadata which is not used in student t distribution
         :returns: Diagonal of hessian matrix (second derivative of likelihood evaluated at points f)
         :rtype: Nx1 array
 
@@ -146,7 +146,7 @@ class StudentT(Likelihood):
         hess = ((self.v + 1)*(e**2 - self.v*self.sigma2)) / ((self.sigma2*self.v + e**2)**2)
         return hess
 
-    def d3logpdf_dlink3(self, link_f, y, extra_data=None):
+    def d3logpdf_dlink3(self, link_f, y, Y_metadata=None):
         """
         Third order derivative log-likelihood function at y given link(f) w.r.t link(f)
 
@@ -157,7 +157,7 @@ class StudentT(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in student t distribution
+        :param Y_metadata: Y_metadata which is not used in student t distribution
         :returns: third derivative of likelihood evaluated at points f
         :rtype: Nx1 array
         """
@@ -168,7 +168,7 @@ class StudentT(Likelihood):
                     )
         return d3lik_dlink3
 
-    def dlogpdf_link_dvar(self, link_f, y, extra_data=None):
+    def dlogpdf_link_dvar(self, link_f, y, Y_metadata=None):
         """
         Gradient of the log-likelihood function at y given f, w.r.t variance parameter (t_noise)
 
@@ -179,7 +179,7 @@ class StudentT(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in student t distribution
+        :param Y_metadata: Y_metadata which is not used in student t distribution
         :returns: derivative of likelihood evaluated at points f w.r.t variance parameter
         :rtype: float
         """
@@ -188,7 +188,7 @@ class StudentT(Likelihood):
         dlogpdf_dvar = self.v*(e**2 - self.sigma2)/(2*self.sigma2*(self.sigma2*self.v + e**2))
         return np.sum(dlogpdf_dvar)
 
-    def dlogpdf_dlink_dvar(self, link_f, y, extra_data=None):
+    def dlogpdf_dlink_dvar(self, link_f, y, Y_metadata=None):
         """
         Derivative of the dlogpdf_dlink w.r.t variance parameter (t_noise)
 
@@ -199,7 +199,7 @@ class StudentT(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in student t distribution
+        :param Y_metadata: Y_metadata which is not used in student t distribution
         :returns: derivative of likelihood evaluated at points f w.r.t variance parameter
         :rtype: Nx1 array
         """
@@ -208,7 +208,7 @@ class StudentT(Likelihood):
         dlogpdf_dlink_dvar = (self.v*(self.v+1)*(-e))/((self.sigma2*self.v + e**2)**2)
         return dlogpdf_dlink_dvar
 
-    def d2logpdf_dlink2_dvar(self, link_f, y, extra_data=None):
+    def d2logpdf_dlink2_dvar(self, link_f, y, Y_metadata=None):
         """
         Gradient of the hessian (d2logpdf_dlink2) w.r.t variance parameter (t_noise)
 
@@ -219,7 +219,7 @@ class StudentT(Likelihood):
         :type link_f: Nx1 array
         :param y: data
         :type y: Nx1 array
-        :param extra_data: extra_data which is not used in student t distribution
+        :param Y_metadata: Y_metadata which is not used in student t distribution
         :returns: derivative of hessian evaluated at points f and f_j w.r.t variance parameter
         :rtype: Nx1 array
         """
@@ -230,18 +230,18 @@ class StudentT(Likelihood):
                            )
         return d2logpdf_dlink2_dvar
 
-    def dlogpdf_link_dtheta(self, f, y, extra_data=None):
-        dlogpdf_dvar = self.dlogpdf_link_dvar(f, y, extra_data=extra_data)
+    def dlogpdf_link_dtheta(self, f, y, Y_metadata=None):
+        dlogpdf_dvar = self.dlogpdf_link_dvar(f, y, Y_metadata=Y_metadata)
         dlogpdf_dv = np.zeros_like(dlogpdf_dvar) #FIXME: Not done yet
         return np.hstack((dlogpdf_dvar, dlogpdf_dv))
 
-    def dlogpdf_dlink_dtheta(self, f, y, extra_data=None):
-        dlogpdf_dlink_dvar = self.dlogpdf_dlink_dvar(f, y, extra_data=extra_data)
+    def dlogpdf_dlink_dtheta(self, f, y, Y_metadata=None):
+        dlogpdf_dlink_dvar = self.dlogpdf_dlink_dvar(f, y, Y_metadata=Y_metadata)
         dlogpdf_dlink_dv = np.zeros_like(dlogpdf_dlink_dvar) #FIXME: Not done yet
         return np.hstack((dlogpdf_dlink_dvar, dlogpdf_dlink_dv))
 
-    def d2logpdf_dlink2_dtheta(self, f, y, extra_data=None):
-        d2logpdf_dlink2_dvar = self.d2logpdf_dlink2_dvar(f, y, extra_data=extra_data)
+    def d2logpdf_dlink2_dtheta(self, f, y, Y_metadata=None):
+        d2logpdf_dlink2_dvar = self.d2logpdf_dlink2_dvar(f, y, Y_metadata=Y_metadata)
         d2logpdf_dlink2_dv = np.zeros_like(d2logpdf_dlink2_dvar) #FIXME: Not done yet
         return np.hstack((d2logpdf_dlink2_dvar, d2logpdf_dlink2_dv))
 
@@ -260,8 +260,16 @@ class StudentT(Likelihood):
     def conditional_mean(self, gp):
         return self.gp_link.transf(gp)
 
+<<<<<<< HEAD
+    def predictive_mean(self, mu, sigma):
+        """
+        Compute mean of the prediction
+        """
+        return mu
+=======
     def conditional_variance(self, gp):
         return self.deg_free/(self.deg_free - 2.)
+>>>>>>> a3287c38ea775155df4e90f7fe1883d12ffb54b9
 
     def samples(self, gp, Y_metadata=None):
         """
diff --git a/GPy/testing/likelihood_tests.py b/GPy/testing/likelihood_tests.py
index 461a00c4..a0c113fe 100644
--- a/GPy/testing/likelihood_tests.py
+++ b/GPy/testing/likelihood_tests.py
@@ -255,25 +255,25 @@ class TestNoiseModels(object):
                             "Y": self.binary_Y,
                             "ep": False # FIXME: Should be True when we have it working again
                             },
-                        #"Exponential_default": {
-                            #"model": GPy.likelihoods.exponential(),
-                            #"link_f_constraints": [constrain_positive],
-                            #"Y": self.positive_Y,
-                            #"laplace": True,
-                        #},
-                        #"Poisson_default": {
-                            #"model": GPy.likelihoods.poisson(),
-                            #"link_f_constraints": [constrain_positive],
-                            #"Y": self.integer_Y,
-                            #"laplace": True,
-                            #"ep": False #Should work though...
-                        #},
-                        #"Gamma_default": {
-                            #"model": GPy.likelihoods.gamma(),
-                            #"link_f_constraints": [constrain_positive],
-                            #"Y": self.positive_Y,
-                            #"laplace": True
-                        #}
+                        "Exponential_default": {
+                            "model": GPy.likelihoods.Exponential(),
+                            "link_f_constraints": [constrain_positive],
+                            "Y": self.positive_Y,
+                            "laplace": True,
+                        },
+                        "Poisson_default": {
+                            "model": GPy.likelihoods.Poisson(),
+                            "link_f_constraints": [constrain_positive],
+                            "Y": self.integer_Y,
+                            "laplace": True,
+                            "ep": False #Should work though...
+                        },
+                        "Gamma_default": {
+                            "model": GPy.likelihoods.Gamma(),
+                            "link_f_constraints": [constrain_positive],
+                            "Y": self.positive_Y,
+                            "laplace": True
+                        }
                     }
 
         for name, attributes in noise_models.iteritems():