Exam 2 Flashcards
what is a disadvantage and advantage of group design
Advantage- be more generalizable if equivalence is met for groups
Disadvantage- could potentially cost more and take more time
what are the three treatment E’s?
Efficacy, Effectiveness, Efficiency
the results of a study can be generalized to a people with similar characteristics
logical generality (external validity)
What are the three factors that influence statistical outcomes?
- effect size
- variability of scores
- sample size
Data are approximately normally distributed is called what?
parametric statistics
what are the four basic components of a methods section?
- subjects/participants
- experimental materials: DV(s), IV(s), testing materials
- Procedure (step-by-step procedure to gather and analyze data)
- data analyses/statistical analyses
this also refers to generality: the results be
extended to other experimenters,
subjects, settings, etc
external validity
non-parametric statistic method to determine correlation
contingency coefficient (C) & spearman rank (rho)
What is the parametric statistic method to determine means in between-subject design?
independent t-test
Measures the difference between two means (e.g., treatment vs. control group) relative to the pooled standard deviation
What effect size?
cohen’s d
two IV;s, with two or more levels is what type of ANOVA?
two-way
parametric statistic method to compare the means within design
paired t-test (two data sets) and repeated ANOVA/MANOVA (> 2 data sets)
One threat to external validity is the Hawthorne effect. What is the Hawthorne effect?
The Hawthorne effect is when a participant may act differently when they know they are being “watched” in a study. It is an external validity threat to experiments.
the results of a study can be generalized to the population
inferential generality (external validity)
comparing the mean of two groups
independent t-test
what is the effect of one of your IVs on the DV
main effect
What are the key elements of the ‘discussion’ section in research articles (7 total)?
- state major findings
- explain meaning and important of the findings
- related to findings of similar studies?
- consider alternative explanations for findings
- state the clinical relevance of the findings
- study’s limitations
- suggestions for further research
how can you control external validity better?
- subject randomization
- larger sample size
what is inferential statistics?
generalize from sample to population, make predictions
compare the means of two groups
independent t-test
taking a test once may affect subsequent administrations of that test. It is directly related to “Within or repeated measures”.
what internal validity?
reactive pretest
more than two IV’s, with two or more levels is what type of ANOVA?
multi-way
t-test, ANOVA, regression, CIs are examples of what type of statistics?
inferential
what are the threats to internal validity?
History
Maturation
Reactive Pretest
Instrumentation
Statistical Regression
Differential subject selection
Attrition
interaction of Factors
non-parametric statistic method to compare means between design
Mann-Whitney U test for two data sets
control group not matched to Tx group is what type of experimental design?
quasi-experimental
what should you include in the subjects/participants section of the methods section?
- inclusion/exclusion criteria
- sample size
- IRB approval?
why is measuring baseline important for a study?
provides a point of reference to determine changes or improvements during the treatment. It helps ensure that any observed effects in the dependent variable are due to the manipulation of the independent variable(s) rather than other extraneous factors. Without a baseline, it is difficult to attribute changes solely to the treatment.
mean, median, mode, range, variance, SD are what type of statistics?
descriptive
what are the two experimental validities related to subjects?
internal and external