Research Methods- Choosing a statistical test Flashcards
Levels of measurement -
Quantitative data can be. classified into types or levels of measurement, such as nominal, ordinal and interval.
Statistical tests -
Used in psychology to determine whether a significant difference or correlation exists (and consequently, whether the null hypothesis should be rejected or retained).
Mann-Whitney -
A test for a significant difference between two sets of scores. Data should be at least ordinal level using an unrelated design (independent groups).
Chi-Squared -
A test for an association (difference or corrclation) between two variables or conditions. Data should be nominal level using an unrelated (independent design.
Pearson’s r -
A parametric test for correlation when data is at interval level.
Related T-test -
A parametric test for difference between two sets of scores. Data must be interval with a related design, ie. repeated measures or matched pairs.
Sign test -
A statistical test used to analyse the difference in scores between related items (e.g. the same participant tested twice). Data should be nominal or better.
Spearman’s rho -
A test for correlation when data is at least ordinal level.
Unrelated T-test -
A parametric test for difference between two sets of scores. Data must be interval with an unrelated design, ie. independent groups.
Wilcoxon -
A test for a significant difference between two sets of scores. Data should be at least ordinal level using a related design (repeated measures).
What is the purpose of statistical testing in psychology?
Statistical testing is used to determine whether a difference or association found in an investigation is statistically significant, meaning it is unlikely to have occurred by chance.
What are the three factors used to decide which statistical test to use?
- Whether the researcher is looking for a difference or a correlation.
- The experimental design used (related or unrelated).
- The level of measurement of the data (nominal, ordinal, or interval).
What is the first factor to consider when choosing a statistical test?
The first factor is whether the researcher is looking for a difference or a correlation, which is usually evident from the hypothesis.
What are the three types of experimental design?
The three types of experimental design are independent groups, repeated measures, and matched pairs.
What is a related design in experimental research?
A related design includes repeated measures (same participants in all conditions) and matched pairs (participants matched on a key variable), as both involve some form of relationship between conditions.
What is an unrelated design in experimental research?
An unrelated design refers to independent groups, where different participants are used in each condition.
What mnemonic can be used to remember the table for choosing a statistical test?
The mnemonic is “CRAZY SEXY CATS MAKE WILD SOUNDS UNDER RED PILLOWS.”
What statistical test is used for nominal data in a test of difference with a related design?
The Sign test is used for nominal data in a test of difference with a related design.
What statistical test is used for nominal data in a test of difference with an unrelated design?
The Chi-Squared test is used for nominal data in a test of difference with an unrelated design.
What statistical test is used for nominal data in a test of association/correlation?
The Chi-Squared test is used for nominal data in a test of association/correlation.
What statistical test is used for ordinal data in a test of difference with an unrelated design?
The Mann-Whitney U test is used for ordinal data in a test of difference with an unrelated design.
What statistical test is used for ordinal data in a test of difference with a related design?
The Wilcoxon signed-rank test is used for ordinal data in a test of difference with a related design.
What statistical test is used for ordinal data in a test of correlation?
Spearman’s rho is used for ordinal data in a test of correlation.
What statistical test is used for interval data in a test of difference with an unrelated design?
The unrelated t-test is used for interval data in a test of difference with an unrelated design.
What statistical test is used for interval data in a test of difference with a related design?
The related t-test is used for interval data in a test of difference with a related design.
What statistical test is used for interval data in a test of correlation?
Pearson’s r is used for interval data in a test of correlation.
What are the three levels of measurement in quantitative data?
The three levels of measurement are nominal, ordinal, and interval.
What is nominal data?
Nominal data is categorical data where items are divided into distinct categories (e.g., people who like cats, dogs, or neither).
What is ordinal data?
Ordinal data is ordered data, such as ratings on a scale (e.g., 1 to 10), but the intervals between values are not equal or precisely defined.
Why is ordinal data sometimes called “unsafe” data?
Ordinal data is considered “unsafe” because it lacks precision and is based on subjective opinions rather than objective measures.
What is interval data?
Interval data is numerical data with equal, precisely defined units (e.g., time, temperature, weight), making it the most precise form of data.
What measure of central tendency is used for nominal data?
The mode is used as the measure of central tendency for nominal data.
What measure of central tendency is used for ordinal data?
The median is used as the measure of central tendency for ordinal data.
What measure of central tendency is used for interval data?
The mean is used as the measure of central tendency for interval data.
What measure of dispersion is used for ordinal data?
The range is used as the measure of dispersion for ordinal data.
What measure of dispersion is used for interval data?
The standard deviation is used as the measure of dispersion for interval data.
