Experimental Psychology Flashcards
What are the three types of psychological research strategies?
Descriptive research
Predictive research
Explanatory research
What kind of psychological research is used for experimental method?
Explanatory research
What is kurtosis?
The shape of the distribution
If I have a set of ordinal data that included extreme score, which measure of enteral tendency should be used?
The median
What are the two comparisons made in a one sample z-score?
Comparing a group to a population
What is a disadvantage as using the mean as a measure of central tendency?
It is effected by extreme scores
Estimates of the mean, median, mode and standard deviation for the population are known as what?
Parameters
Describe the mean absolute deviance?
How far away a particular score is from the mean, but does not included a direction
Describe a population?
The set of scores we are interested in on any given variable
What are the types of non probability samples?
Convenience sampling
Quota sampling
Purpose sampling
Snowball sampling
What is standard error?
The standard deviation of a large group of means.
What is a confident interval?
A range in which the parameter is likely to fall into. Usually around 95%
What is power?
The probability of correctly rejection a false null hypothesis
What is the sampling distribution of the mean?
The distribution you would get if you drew an infinite number of samples for the population and calculated the mean for each
What is the only time when z-scores should be used?
When the population mean and standard deviation are known.
How do you calculate standard deviation for a t-test?
By making an estimate based on our sample standard deviation.
What are degrees of freedom?
Where the sample size is compared against the t-table
Describe what a z score is
A mean score versus the population mean, relative to the population standard deviation
What is the difference between a one sample t test and a paired sample t test?
One sample t test compares two scores. A paired samples t test compares the difference between two scores, as the same people are measured twice
What is the difference between an independent samples t test and a paired samples t test?
An independent samples t test is the means of group one versus the mean of group two. A paired samples t test it the difference is score pre and post.
What types of data are used for parametric tests?
Interval or ratio data
Describe the central limit theorem
- Is what is used to find the mean and standard deviation of the sample distribution.
How does central limit theorem explain how to calculate the standard deviation of the sample distribution?
The standard deviation of a sample distribution is the population standard deviation, divided by the square root of N
What is standard error of the mean?
The standard distribution of the sampling distribution of the mean
Explains the conceptual model of the one way between subjects ANOVA.
You = the population mean + the effective of the treatment group + the difference between your score and the group mean (part special to you)
When would you conduct a one way ANOVA?
When your IV had more than two levels
Describe MS error
Is an estimate of the population variance, which is not affected by the null hypothesis
Describe MS treatment?
Another measure of population variance, however assumes that the null hypothesis is true. Also includes the effect of the treatment
How is the F value calculated?
MS treatment divided by MS error
How is eta-squared calculate?
SS treatment divided by SS total (on SPSS output)
What are the two types of post hoc tests used in this unit
S-N-K and Scheffe
Describe familywise error rate
The higher probability of a type 1 error when running many comparisons
When does cohens D need to be calculated?
In an independent samples t-test
Describe a one way repeated measures ANOVA
When there are more than two or more levels of one IV and it is manipulated within subjects
What is the most significant advantage of using a one way repeated measures ANOVA?
It is easier to find a significant difference by measure the same people twice
What is the difference in error rates between one way between subject ANOVA and repeated measures ANOVA?
Error size can be reduced in a repeated measures ANOVA, by removing the contribution made by individual differences
Describe the structural model of a one way repeated measures ANOVA
Score = overall mean + the fact that they’re measures twice + the effect of the condition they’re in + the bit that is specific for that person AT that treatment level
What does individual difference refer to in a one way repeated measures ANOVA
Because we are able to measure people twice, we can calculated characteristics that are specific to them
The variation between one group of scores should be approximately equal to the variability of any other group of scores. What is this?
Sphericity
Describe a factorial ANOVA
For experimental designs that have more than one IV
What are the three types of factorial ANOVAs
Between subjects
Within subjects
Mixed
How many levels of MS treatment are calculated in a between groups factorial ANOVA with two IV’s
3 - one for each IV and another for the interaction
What is used to follow up a significant interaction
Syntax (MANOVA)
What follow up test would be used for a factorial mixed groups ANOVA when the interaction was significant
The file would be split, and a t test would be conducted if the IV only had two levels. If it had more levels a one way ANOVA
