# W2D3 -- DecisionMaking: Erratum

There are a few things in the tutorial notebook which have been flagged, but will unlikely be fixed before the tutorial. Putting them here for reference.

## Bugs:

(report potential bugs / errors here (ideally along with a solution))

Tutorial 1, section 1.1 equation (5) – mu_1 to be changed to mu_R

tutorial 2, equation 1.

sum should be over i, not over j

## Clarifications / Inconsistencies:

(report when something needs clarification (+suggest a clarification))

Tutorial 1, Exercise 2: It would be nice to have a definition of ‘accuracy’ somewhere, given that this needs to be calculated in the exercise.

Tutorial 1, Exercise 4 : Is there a reason why the average accuracy is represented wrt the decision speed while it was represented wrt to the decision time in exercise 2? I find it quite confusing. Moreover, I found that the way the decision speed is computed (as being the inverse

of decision time) makes it very hard to interpret.

Tutorial 3, exercise 1.

Defining state[0] in the solutions is set to mu_0, on the equations it sampled from a multivariate gaussian N(mu_0,sigma_0). Consistent solution:

State[0] = stats.multivariate_normal(mean=params[‘mu_0’],cov=params[‘sigma_0’]).rvs(1)

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