Research methods: แบบฝึกหัด

In research methods, what is the name of the sampling technique where every member of the target population has an equal chance of being selected?

A researcher conducted a study to see if there was a relationship between the number of hours spent studying and exam scores. The results showed that as study hours increased, exam scores also increased. Which type of correlation does this describe, and which chart would best display this data?

What is meant by the term stratified sampling in psychological research?

A researcher finds a strong correlation between sleep and test scores. If \( n = 20 \) students are plotted on a graph with sleep hours on the x-axis and scores on the y-axis, what specific quantitative display is used, and what does a negative correlation indicate in this context?

A researcher conducted a study into the effects of sleep on memory. They split participants into two groups: Group A had 8 hours of sleep, while Group B had 4 hours of sleep. All participants then had to recall a list of 20 words.

a) Identify the independent variable and the dependent variable in this study. (2 points)
b) Briefly explain one possible extraneous variable that could affect the results of this study. (1 point)

A psychologist wants to investigate if there is a relationship between the age of a child and the number of words they can remember from a list. They decide to use a correlation.

a) Explain the difference between a null hypothesis and an alternative hypothesis for this study. (2 points)
b) The researcher intends to use stratified sampling to select participants from a local primary school. Describe how this sampling method would be carried out. (2 points)
c) Identify which quantitative display would be most appropriate to show the relationship between the two variables in this study. (1 point)