PYC3704 Psychological Research (2021 - Semester 1 and Semester 2 - Assignment 3)

PYC3704 – Psychological Research 2021 – Semester 1 and Semester 2 – Assignment 3 Question #1: Which of the following are advantages of studying statistical methods in psychology? 1. it leads to a better understanding of the content of psychological theories. 2. it helps us to formulate research questions. 3. it helps us to evaluate whether the patterns we observe in data are due to more than the consequence of chance. 5. it gives insight into the nature of the scientific process. Question #2 Which of the options below is a valid description of a ‘construct’ in psychological research? It is a(n) ... 1. measurement based on the careful observation of aspects of humans or human behaviour 2. observation of an aspect of humans or human behaviour which was operationalized in some way 3. hypothetical aspect of humans or human behaviour which we wish to investigate 4. explanation of empirical observations based on the measurement of certain variables Question #3: 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 ... 1. measured sports performance; social skills 2. type of sports; social skills 3. social skills; measured sports performance 4. social skills; type of sports Question #4: A psychologist studies the effect that age has on attitude towards Aids. She selects a sample of subjects divided into three different age groups, 20-30 years, 30-40 years and 40-50 years. The three age groups are ... 1. different variables for measuring ‘age’ 2. operationalisations of the variable ‘age’ 3. three different theoretical constructs 4. a way of measuring ‘age’ Question 5: The term ‘inference’ in psychological research refers to ... 1. describing information in a precise way 2. making a prediction or generalization based on existing information 3. the procedures for making a construct visible so that a measurement can be made 4. the development of a hypothesis as a relationship among variables Question 6: 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. 1. (a) but not (b) 2. both (a) and (b) 3. (b) but not (a) 4. neither (a) nor (b) Question 7: A psychologist uses a psychometric test to study the intelligence of school children. Intelligence is the ... variable and the psychometric test represents the ... variable in this study. 1. independent; dependent 2. manifest; operational 3. dependent; independent 4. latent; manifest Question 8: In the process of psychological research, researchers try to ... 1. prove that a theory is true 2. account for theoretical assumptions 3. obtain empirical support for a theory 4. change hypotheses into theories Question 9: If a coin is flipped three time, the sample space of possible outcomes is: 1. HHH; TTT; THT; HTH; HHT; TTH; HTH 2. HHH; HHT; HTH; HTT; THH; THT; TTH; TTT 3. HTT; THT; HTH; HHH; TTH; TTT 4. HHH; HTT; HTH; TTT; HTT; THH; HHT; THT Question 10: An industrial psychologist wants to investigate the levels of assertiveness among different categories of workers in a large company. He draws a sample of 200 workers and then divides them into managers, clerical workers, technical workers and manual workers with the intention of getting each participant to do a test to determine their level of assertiveness. The division of workers into these four groups represents a measurement on a ... level. 1. nominal 2. ordinal 3. interval 4. ratio Question 11: 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 ... 1. 0.60; 0.04 2. 0.07; 0.50 3. 0.04; 0.60 4. 0.60; 0.05 Question 12: In response to a questionnaire, 57 people answered “yes” to a particular question. Of these, 8 persons were male. There were 61 people that answered “no” to the question, and 5 of these were male. If one person is selected randomly from the group, what is the probability that the person answered “yes” or was male? 1. o.14 2. 0.525 3. 0.593 4. 0.11 Question 13: A teacher is teaching a class about probabilities. She shows the learners a bowl which contains 3 Red marbles, 5 Blue marbles and 7 Yellow marbles. One of the learners, Vusi, is asked by the teacher to select one marble out of the bowl at random and to hand it to her. She shows the class that Vusi chose a Blue marble and she demonstrates to the class how to calculate the probability of this outcome. While holding on to the first marble, she asks Vusi to select another marble in the same way. She now asks the class to calculate the probability that both the first and the second marble chosen by Vusi would happen to be Blue. Select the best estimate out of the options given below: 1. 0.1333 2. 0. 1111 3. 0.6190 4. 0.0952 Question 14: The z-score corresponding to a raw score represents the number of ... that the raw score differs from the mean of the raw score distribution. 1. points 2. standard deviations 3. percentiles 4. variances Question 15: A test statistic is defined as ... 1. The quantity that is calculated to test a statistical hypothesis, by making use of the sample statistics. 2. The quantity that is calculated to test a statistical hypothesis, by making use of the population statistics. 3. A descriptive statistic that describes an aspect of the sample data. 4. A parametric statistic that describes an aspect of the population data. Question 16: A researcher would like to investigate the relationship between weight gain and physical activities 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 ... 1. weight gain; physical activities 2. physical activities; weight gain 3. gender; socio-economic backgrounds 4. weight gain; gender Question 17: The sampling distribution of means refers to: 1. the normal distribution of a raw score distributed around the mean. 2. the distribution of the different possible values of the sample means together with their respective probabilities of occurrence. 3. the distribution of the values of the items in the population. 4. the distribution of the means of all possible samples of a particular size randomly selected from the same population. Question 18: The size of the p-value depends on ... 1. a choice made by the researcher 2. conventional rules 3. the null hypothesis 4. the value of the test statistic Question 19: Which of the following statements regarding errors of measurement are true? (a) Errors of measurement arise because the measurement of psychological constructs are imprecise. (b) There is always an error hidden in the measurement of psychological constructs arising from extraneous variables. (c) Psychological constructs are measured based on a sample of data that only reflects the population to a certain degree. (d) Probability theory is a tool used by statisticians to completely eradicate such errors during the computation of sample statistics. 1. (a), (b) and (c) 2. (a), (c) and (d) 3. (b), (c) and (d) 4. None of the above Question 20: The lower we set the level of significance, the greater the probability ... 1. rejecting the null hypothesis 2. a Type II error 3. a Type I error 3. accepting the alternative hypothesis Answer Questions 21 to 25 on the basis of the following scenario: 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. Question 21: Which kind of hypothesis must be set up by Lebo for testing? 1. A directional hypothesis. 2 . A nondirectional hypothesis. 3. Lebo can set up either a directional or a nondirectional hypothesis, depending on how she chooses to formulate her question. 4. Not enough information is given to decide. Question 22: Which of the sets of statistical hypotheses below reflect the research hypothesis to be tested? 1. H0: μ = 50 H1: μ > ¯x 2. H0: μ = 50 H1: μ ≠ 50 3. H0: μ = 50 H1: μ > 50 4. H0: μ = 50 H1: μ < 50 Question 23: After Lebo collected the responses on the work motivation questionnaire for an appropriate sample of 100 workers from small companies, she calculates the following sample parameters: Sample size: n = 100. Mean motivation score for small companies: x̄ = 55.2. Standard deviation of the motivation score for small companies: s = 12.5. Since the mean and standard deviation for large companies are given (as 50 and 15 respectively), Lebo decides to use a single-sample z-test (i.e. the z_(x̄) test statistic) to test whether the mean motivation scores for small companies differ significantly from the mean motivation scores for large companies. Which of the following are closest to the calculated value of this statistic? 1. 0.42 2. 41.6 3. 4.16 4. 3.47 Question 24: If Lebo tests this hypothesis against a significance level of α = 0.01, what can she conclude about the motivation level of small companies? 1. The null hypothesis can be rejected, so it follows that the motivation level is higher in small companies than in larger ones. 2. The null hypothesis cannot be rejected, so it follows that the motivation level is no higher in small companies than in larger ones. 3. The null hypothesis can be rejected, so it follows that the motivation level is higher in larger companies than in smaller ones. 4. The alternative hypothesis is not valid, so it follows that the motivation level is higher in small companies than in larger ones. Question 25: Lebo wants to determine whether the difference between the motivation level for small companies and those for large companies is reasonably large, in terms of its practical implication, irrespective of whether it is significant or not. After making the appropriate calculations, what does she find? The effective difference between the motivation level for small companies and those for large companies is ... 1. very small 2. between small and medium 3. between medium and large 4. very large Question 26: 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? 1. There is no relationship between depression and anxiety and any observed relationship is the result of chance. 2. Individuals with lower levels of depression will have higher levels of anxiety while any result otherwise observed is the product of chance. 3. Individuals with higher levels of depression will have lower levels of anxiety while any relationships otherwise observed are the result of chance or measurement error. 4. There will not be a significant difference between those individuals who score high on depression in comparison to those individuals who score high on anxiety. Any observed difference is the result of chance alone. Use the scenario below to answer Question 27 to 30: 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 x̄ = 58.4 and standard deviation of s = 16.8 is found. She plans to test the hypothesis at α = 0.05. Question 27: The appropriate research hypothesis suggested by the scenario above is as follows: 1. Cognitive functioning declines with age. 2. The cognitive functioning of elderly persons is related to their perceptual speed. 3. Cognitive functioning will be better for elderly persons who take the dietary supplement than for those who do not. 4. The perceptual speed of elderly persons who take the dietary supplement will be less than for those who do no. Question 28: With the information as given in the scenario, which of the statistical tests listed below would be the most appropriate statistical test for Lebo to use to test the hypothesis? 1. A one sample t-test comparing the sample to the population. 2. A two sample t-test comparing age groups. 3. A test of the significance of the correlation r between variables age and perceptual speed. 4. A one sample z-test for comparing the sample to the population. Question 29: Lebo calculates the standard error of the sampling distribution of the mean. She finds σ_(x̄) = ... 1. 16.8 2. 1.5 3. 15 4. 1.68 Question 30: Although she finds that the statistical test gives a significant result, Lebo wants to determine whether the difference between the performance of her sample and elderly people in general is reasonably important in terms of its practical implication, irrespective of the size of the sample. Given the available information, what should she conclude? The effective difference between the performance of the elderly people tested by Lebo and elderly people in general is - - - - -. 1. obviously important if it was found to be significant 2. rather small 3. around medium 4. very large