Question:

In the article by Gadd and Phipps (2012), they refer to the challenges faced by psychological and, specifically, neuropsychological assessment. Their study focused on a preliminary standardisation of the Wisconsin Card Sorting Test (a non-verbal measure) for Setswana-speaking university students. The US normative sample is described as participants (N = 899) from both genders who were screened beforehand to exclude individuals with a history of neurological, learning, emotional and attention difficulties. The South African sample consisted of university students (N = 93) from both genders, between the ages of 18 and 29, who were screened in terms of hearing and visual impairments and any history of psychiatriceurological difficulties. The latter was done to prevent contamination of the results by these variables. The students were from the University of Limpopo, Medunsa Campus. Answer Questions 1 to 5.

Question 5

Gadd and Phipps (2012) found that the results of the South African sample on the Wisconsin Card Sorting Test did not resemble a normal distribution and could not be converted to a normal distribution. This implies that the ...

(1) mean performance of this sample cannot be calculated

(2) standard deviation will differ below and above the mean

(3) mean and standard deviation do not provide a predetermined distribution of performance

(4) results cannot be replicated

Would 1 be the correct answer?

2. (15 pts) Consider a Markov chain { Xn } with state space S = {0, 1, 2} and transition matrix and transition matrix P = O ON/H HNIH O (1) Let the mapping f : S - S satisfy f(0) = 0 and f(2) = 1 and assume that f(1) + f(2). If Yn = f(Xn), then when is { Yn } a Markov chain? Is { Yn } always a Markov chain? In other words, are functions of Markov chains always Markov chains?1. (a) Explain what is meant by the transition probability matrix of a homogeneous Markov chain. [5 marks] (b) Explain what is meant by the stationary distribution of a Markov chain? [5 marks] (c) A Markov chain has transition probability matrix, A, with entries Ouj; and stationary distribution . Write down an expression for the entries of the reverse Markov chain. [5 marks (d) Consider the following transition probability matrix of a homogo- neous Markov chain, with three states i,j and k (the TPM is in that order). If the stationary vector of the chain is (1/9, 2/9, 2/3), determine whether the Markov chain is reversible. 1 /0.2 0.2 0.6 0.1 0.6 0.3 4 \\0.1 0.1 0.8 [5 marks] (e) Let X1, X2, Xa be a sequence of random variables resulting from the above Markov chain. If X1 = i and Xs = j what is the probability that X2 = k? [5 marks]Which of the following is an advantage of multivariate correlational research over bivariate correlational research? O Bivariate correlational studies help address internal validity, whereas multivariate correlational studies do not. Multivariate correlational studies establish covariance, whereas bivariate correlational studies do not. O Some multivariate correlational studies help to address temporal precedence, whereas bivariate correlational studies do not. Multivariate correlational studies help to address external validity, whereas bivariate correlational studies do not