STATS & RMS Flashcards
What is the difference between a between-subjects design and a within-subjects design?
A between-subjects design, (or a between-groups design) every participant experiences only one condition, and you compare group differences between participants in various conditions.
In a within-subjects design, every participant experiences every condition.
What is an ANOVA test used for?
An ANOVA test is used to compare the means of three or more groups to determine if there are significant differences between them.
What is a mediator/ Mediation?
CAUSE
A Mediator is the reason for the effect the IV has on the DV.
i.e.: if the IV is curiosity, and the DV is learning, then the mediator is ‘discovery’, because the reason curiosity has an effect on learning, is because curious people are more likely to discover new things, and learn. The act of discovery is what is causing it.
What is a Moderator/Moderation?
EFFECT SIZE
Moderators contextualise the event , i.e.: if curiosity is the IV, and learning is the DV, then ‘distractions’ could be the moderator. I.e dampen the positive relationship between curiosity and learning.
A moderator must NOT be the causal result of the IV.
What is a Factorial/2-factor ANOVA used for?
When comparing groups based on 2 or more independent variables.
What is a single-factor ANOVA used for?
When comparing three or more groups, with 1 independent variable.
What does a One-Way Between-Subjects ANOVA do?
A One-Way Between-Subjects ANOVA compares the means between more than two independent groups, such as comparing the difference between groups A, B and C.
What is a One-Way Within-Subjects ANOVA ?
A One-Way Within-Subjects (repeated measures) ANOVA is used to determine whether three or more group means are different where the participants are the same in each group.
What is a co-variable?
The variables investigated in a correlation.
What is a correlational analysis?
A mathematical technique where the researcher looks to see whether scores for two co-variables are related.
What is counterbalancing?
A way of trying to control for order effects in a repeated measures design, e.g. half the participants do condition A followed by B and the other half do B followed by A.
What is the critical value?
A critical value is the value of the test statistic which defines the upper and lower bounds of a confidence interval, or which defines the threshold of statistical significance in a statistical test.
What are demand characteristics?
Demand characteristics occur when participants try to make sense of the research situation they are in and try to guess the purpose of the research or try to present themselves in a good way.
What is the dependant variable?
The variable that is measured to tell you the outcome.
What is a directional hypotheis?
A one-tailed hypothesis that states the direction of the difference or relationship (e.g. boys are more helpful than girls).
What is a dispersion measure?
A dispersion measure shows how a set of data is spread out, examples are the range and the standard deviation.
What is a double-blind control?
Participants are not told the true purpose of the research and the experimenter is also blind to at least some aspects of the research design.
What is ecological validity?
The extent to which the findings of a research study are able to be generalized to real-life settings.
What are the 3 main ethical issues in research?
There are 3 main ethical issues that occur in psychological research – deception, lack of informed consent and lack of protection of participants.
What is evaluation apprehension?
Participants’ behaviour is distorted as they fear being judged by observers.
What is the experimental group?
The group that received the experimental treatment (e.g. sleep deprivation).
What is external validity?
Whether it is possible to generalise the results beyond the experimental setting.
What is an extraneous variable?
Variables that if not controlled may affect the DV and provide a false impression than an IV has produced changes when it hasn’t.
What is a Quasi experiment?
An experiment often conducted in controlled conditions where the IV simply exists so there can be no random allocation to the conditions. (often you would recruit a target sample).
What is reliability?
Whether something is consistent. In the case of a study, whether it is replicable.
What is a representative sample?
A sample that that closely matched the target population as a whole in terms of key variables and characteristics.
What is a sample?
A group of people that are drawn from the target population to take part in a research investigation.
What is a sign test?
A statistical test used to analyse the direction of differences of scores between the same or matched pairs of subjects under two experimental conditions.
What is the meaning of significance?
If the result of a statistical test is significant it is highly unlikely to have occurred by chance.
What is validity?
Whether something is true – measures what it sets out to measure.
Nominal data is…?
Data are catergories with no ranking, e.g.: sex, religion.
Ordinal data is…?
Data are categories that have some intrinsic ranking, i.e.: attiude scores, satisfaction ratings.
Continuous scale data is…?
Data are ordered categories with a meaningful metric, e.g.: age in years, income in thousands of dollars.
what does ‘r’ represent in correlational analysis?
the strength and direction of the linear correlation (relationship). e.g.: 0.99 = strong positive. -0.99 = strong negative. 0 = no relationship.
what is “p” in correlational analysis?
“p” is the population correlation.
What is a “Pearsons” test/what does it do?
The “Pearson” correlation coefficient (r) is the most common way of measuring a linear correlation.
It is a number between –1 and 1 that measures the strength and direction of the relationship between two variables.
What is a covariant?
A covariant is a measure of the relationship between two random variables.
what is “determinism” ?
determinism is the assumption that all events have causes.
what is “empiricism” ?
empiricism is the process of learning things through direct observation.
What is validity ?
Validity refers to the accuracy of research.
What is reliability?
Reliability refers to the consistency of research.
What kind of variables does experimental research always involve?
Experimental research always involves a manipulated variable, also called an experimental factor or independent variable.
What kind of variables does correlational research focus on?
correlational research focuses on subject variables, that vary across individuals and situations i.e.: attributes that pre-exist the study or attributes that occur naturally during the study. E.g.: age/sex/SES/phone use/gaming.
What is a limitation of a Quasi-Experimental design?
The lack of random assignment in quasi-experimental designs means we need to be more cautious about causal inferences.
What is a correlational design ?
corelational designs involves two or more variables that you cannot manipulate experimentally.
What are two problems to consider related to correlational designs?
1.) Direction of causation problem: a correlation does not indicate which variable is the cause and which is the effect.
2.) Third variable problem: the correlation between 2 variables may be the result of some 3rd (unspecified) variable.
What are 2 cons of observational methods in correlational design?
observational methods involve interpretation and judgement, and they lack a control.
When would you use a non-parametric test?
If you don’t meet the sample size guidelines for the parametric tests and you are not confident that you have normally distributed data, you should use a non-parametric test.
What is a parametric test?
- the data are normally distributed
- the groups that are being compared have similar variance
- the data are independent
What are 2 examples of non-parametric within-subjects test?
-Sign test
-Wilcoxon Matched-Pairs test.
What is an example of a between-subjects Non-parametric test?
-Mann-Whitney U test/Wilcoxon Rank-Sum test.
What are some limitations of the sign-test?
- ignores size difference
- ignores tied scores
- only assess 2 conditions
- the magnitude of the change is ignored ( tells you if there is an effect just not what the effect is).
