public double EstimateBestTheta(List<QuestionInfo> questionHistory, double previousTheta)
{
List<IModelParameters> modelParametersList = questionHistory.Select(x => x.Question.ModelParameters).ToList();
List<int> responseVector = questionHistory.Select(x => (int)x.Score).ToList();
if (IsZeroVarianceReponsePattern(responseVector))
{
return previousTheta + ConstantStep;
}
MaximumLikelihoodEstimator mleEstimator = new MaximumLikelihoodEstimator(modelParametersList);
var mleOfTheta = mleEstimator.GetMle(responseVector);
return mleOfTheta;
}
public double EstimateBestTheta(List <QuestionInfo> questionHistory, double previousTheta)
{
List <IModelParameters> modelParametersList = GetModelParametersList(questionHistory);
//questionHistory.Select(x => x.Question.ModelParameters).ToList();
List <int> responseVector = questionHistory.Select(x => (int)x.Score).ToList();
if (AllResponsesCorrect(responseVector))
{
return(previousTheta + GetIncreasingNonZeroVarianceStep());
}
if (AllResponsesIncorrect(responseVector))
{
return(previousTheta - GetDecreasingNonZeroVarianceStep());
}
MaximumLikelihoodEstimator mleEstimator = new MaximumLikelihoodEstimator(modelParametersList, _gradientDescentTolerance);
var mleOfTheta = mleEstimator.GetMle(responseVector);
return(mleOfTheta);
}