Term
|
Definition
| t-test allows us to compare the means of two groups and determine how likely the difference between the two means occurred by chance. |
|
|
Term
| Paired (or correlated) T-test |
|
Definition
is concerned with the difference between the average scores of a single sample of individuals who is assessed at two different times (such as before treatment and after treatment) or on two different measures. It can also compare average scores of samples
of individuals who are paired in some way (such as siblings, mothers and daughters, persons who are matched in terms of a particular characteristics). |
|
|
Term
| Analysis of Variance (ANOVA) |
|
Definition
2+ more groups being tested.
Tests your Null Hypothesis and your alternative hypothesis.
It will tell your the difference, but it will not tell you how or which one differs. |
|
|
Term
|
Definition
| If you do too many tests on one set of data. If you do three tests then you’d divide your p value= 0.05/3 and that would become your new alpha level or pvalue =.017 |
|
|
Term
|
Definition
|
|
Term
|
Definition
| if there is manipulation and random assignment. – has to be a true exp. |
|
|
Term
| How do you know when you have an interaction |
|
Definition
| If the lines are not paralell, then you have an interaction, even if they are not crossing, they will be crossing eventually |
|
|
Term
|
Definition
| tells you if your data can be applied to the general population or is a result of error. |
|
|
Term
|
Definition
The effect of each of the independent
variables on the dependent variable is the main effect of that variable |
|
|
Term
|
Definition
Internal validity refers to the scientific
accuracy of the study or procedure |
|
|
Term
|
Definition
| threats to internal validity; fatigue, maturation, mortalitiy rate, practice effect, boredum |
|
|
Term
Posttest Only Independent Groups
Design |
|
Definition
| Classic experimental design, two equal groups, randomly tested, no selection differenece,than intro. IV(manipulation) to exp and control group, and then easure effect of IV on DP |
|
|
Term
Pretest-Posttest Independent
Groups Design |
|
Definition
Design:
Group A Pretest- Treatment- Posttest
Group B Pretest- Control - Posttest
Allows you us to see if a change actually occured. difference=(Posttest-Pretest, Allows paticipants with a paticular characteristic. But pretest can effect postest(practice effect, fatigure, maturation, hoistory) |
|
|
Term
| Solomon’s Four-Group Design |
|
Definition
Group A Pretest -Treatment -Posttest
Group B Pretest -No Treatment -Posttest
Group C Treatment -Posttest
Group D No Treatment -Posttest
Allows us to assess whether there is an
interaction between the treatment and the
pretest
If no impact of pretest, posttest scores will be same in
both control groups and both exp groups |
|
|
Term
Matched Pairs with
Random Assignment |
|
Definition
| match variable from each individual, match on relevant variables ( variables likley to affect the dependent measure, show variability in the population |
|
|
Term
|
Definition
Do BOTH MANIPULATION IN ONE GROUP, Each participant goes through all experimental conditions. Get baseline (control) measure of DV
Apply independent variable (manipulation)
Take another measure of DV.
Design:
Control Measure1 Treatment Measure2
Get a difference score
Measure2 – Measure1 = Difference |
|
|
Term
|
Definition
When the order of the treatment has an effect on the treatment. To get rid of this use Latin square design.
gp1-pretest-treatment-test-control-postest
gp2-pretest-control-test-treatment-posttest |
|
|
Term
|
Definition
| Critical to internal validity. Assignment procedures; free random assignment to groups, matched random assignemnt in matched sets to group |
|
|
Term
| Subject Effects/Reactivity |
|
Definition
| Changes in behaviour simply from being studied; physiological changes |
|
|
Term
| Demand Characteristics/social desirability |
|
Definition
| Change their behaviour and performance, because they form an opinion of what the experimentor meant |
|
|
Term
|
Definition
| Treatment effect that is due to expectation that the treatment will work |
|
|
Term
|
Definition
| Keep testing conditions constand for all participants; time of day, lightning, setting, experimenter, instructions given, distractions |
|
|
Term
| How to Control Procedures |
|
Definition
| Control throug the selection and assignment of participants (random or matched), response measurements,replication, Automation ( reduces contact btw participants and exp.), Using objective measures(less judgement by the exper.) |
|
|
Term
|
Definition
| The participant dose not know what condition they are in. |
|
|
Term
|
Definition
| Neither the experimenter nor the participant knows what condition the participant is in. |
|
|
Term
| Multilevel, randomized, between-subjects design. |
|
Definition
Group 1 Pretest Treatment 1 Posttest
Group 2 Pretest Treatment 2 Posttest
Group N Pretest Treatment N Posttest
May or may not include a pretest
Multi-group extension of the basic experimental
designs |
|
|
Term
|
Definition
| Includes two or more IV (essentially 2+ studies in one), interactions effects of the IV |
|
|
Term
|
Definition
| The combined effects of two or more independent variables on the dependent variable is an interaction |
|
|
Term
| Repeated-Measures Factorials |
|
Definition
| Can use a within-subjects(repated measures) desgin in a factorial study. Increases ability to find a significant effect |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| Most frequently occuring number |
|
|
Term
|
Definition
| Difference between the largeest and smallest score in a set |
|
|
Term
|
Definition
| Average distance of the scores from the mean of the set of scores |
|
|
Term
|
Definition
|
|
Term
| Pearson product-moment correlation |
|
Definition
| Measure of relationshhips - with interval or ratio data |
|
|
Term
| Spearman rank-order correlation |
|
Definition
| measure of relationship- used when one variable is ordinal and tbe second is at least ordinal |
|
|
Term
|
Definition
| Visual representation of a correlation, helps to identify nonlinear relationships |
|
|
Term
|
Definition
| finding the best fitting straight line for the data, best in scatter plot |
|
|
Term
|
Definition
| Used to draw inferences about population on the basis of samples fom the populations. the data we do on our data is called the inferential statistics |
|
|
Term
| Testing for Mean Differences |
|
Definition
| T test (for independent groups), Paired t-test, ANOVA |
|
|
