Which of the

following statements regarding errors of measurement are true?

a)        

b)        

c)        

d)        

A test

statistic is defined as

A psychologist believes that

personality factors such as ability to get along with other people in a team

are likely to have an influence their success in a team sport. To investigate

this, she draws a sample of participants in competitive sport, comprising

soccer players, hockey players and cricketers from various sports clubs.  After evaluating their performance on an

appropriate psychometric test, she divides players from the three types of

sports into two groups: those who have good social skills and those who tend

avoid social contact.  She then uses

evaluation forms, based on interviews with different sports experts, to assess

the actual sports performance of the members of the sample.  The dependent variable in the study is - - -

- - and the independent variable is - - - - -.

A researcher

would like to investigate the relationship between watching violent movies and

aggression levels in a sample of university students. The sample consists of

male and female participants from various socio-economic backgrounds. The

independent variable in this study is - - - - - while the dependent variable in

the study is - - - - -.

It is

hypothesised that higher levels of depression are related to higher levels of anxiety.

Considering this research hypothesis, what would the null hypothesis be?

Consider the following statement:

"The experience of strong emotion is accompanied by physiological

reactions such as an increase in heart rate". This statement can be viewed

as a research hypothesis because it - - - - -.

(a)    makes a prediction that can be tested by observation

(b)    describes a possible relationship between variables

Lebo claims that workers in large companies are less work

motivated than workers in small companies. In a previous study involving all

large companies in South Africa, it was found that the average workers’

motivation score on a work motivation questionnaire (where a higher score

indicates a higher level of work motivation) was 50 with a standard deviation

of 15. Lebo plans to present the same questionnaire to a sample of workers from

small companies to determine whether her suspicion is true.

Suppose that 5 000 students wrote the examinations in PYC3714 and that

3000 of them passed, of which 200 obtained exactly 50%. This means that for

randomly selected students the probability of obtaining exactly 50% is - - - -

- while the probability of obtaining 50% or more is - - - - -.

The term ‘inference’ in psychological research refers to - - - - -.

Lebo, a research psychologist, suspects that the addition of

certain food supplements to the diet of elderly people will reduce the decline

in cognitive functioning that comes about because of aging. She decides to test

this using a neuropsychological test that measure perceptual speed (the NPS

test). It is known that the distribution of scores on this test is

approximately normal and that a mean of µ=50 and a standard deviation of σ=15

was found in the population of persons older than 65.

To investigate her hypothesis, Lebo obtains a random sample

of n=100 persons older than 65. Each member of this sample is given a daily

dose of supplements over a period of six months. At the end of this time, each

person is tested on the NPS test and a mean of x¯ = 58.4 and standard deviation

of s = 16.8 is found. She plans to test the hypothesis at α = 0.05.