Stats - Selecting Stats Tests Flashcards
Best measure for central tendency with similar/close scores or values vs best measure for extreme scores or values
Mean is better with similar/close values
Median is better when there are extreme scores/values (i.e., $10,000,000 homes) or substantial percentages of maximum scores
Idiographic
single subject design/approach
Nomothetic
group approaches
What’s Normative data
data that can be compared both within & across subjects
Ipsative data
results from a forced-choice format (can only describe relative strengths/interests within a subject & not used for comparison across subjects)
When conducting a ABAB design you should be concerned with:
failure of DV to return to baseline
What statistical test has nominal data collected for one independent variable?
Chi-Square
What statistical test has nominal data collected for two independent variables?
Multiple Sample Chi-Square
What statistical test has interval or ratio data collected for one group of subjects?
T-Test for Single Sample
What statistical test has interval or ratio data collected for two correlated groups of subjects?
T-Test for Matched or Correlated Samples
What statistical test has interval or ratio data collected for two independent groups of subjects?
T-Test for Independent Samples
What statistical test has interval or ratio data collected for more than two groups of subjects are compared to one independent variable
One-Way ANOVA
What concept refers to the number of possible variations in outcome that can be obtained
Degrees of freedom
What’s the formula to measure the degrees of freedom in a single sample chi-square?
df = # columns - 1
What’s the formula to measure the degrees of freedom for multiple sample chi-square?
df = (# rows - 1) x (# columns - 1)
What formula measures the degrees of freedom for the T-Test for Single Subjects?
df = N (# of subjects) - 1
What formula measures the degrees of freedom for the T-Test for Matched or Correlated Samples?
df = # pairs -1
With One-Way ANOVA, what are the 3 different ways of calculating degrees of freedom?
1. total degrees of freedom
2. degrees of freedom between groups
3. degrees of freedom within groups
- df total = N-1
- df between groups = # groups - 1
- df within groups = df total - df between groups
What’s the formula to calculate the expected frequency in a Chi-Square?
expected frequency = N (sample size) / total # of cells
ex: survey 200 people to see which genders (male or female = 2) vote for Democrat or republican (= 2)
200 / (2 x 2) = 200 / 4 = 50 (expected frequency)
What is the formula to calculate the expected frequency of a Chi-Square when data is given for each cell?
(Sum of Row x Sum of Column) / N (sample size)
What’s the risk of running multiple t-tests instead of one-way ANOVA? *will be on test
increases the probability of making a type 1 error
What’s the possibility of making a Type 1 error if alpha = 0.05 and you run 6 t-tests?
6 (t-tests) x 0.05 = 0.30
What does it mean if the F-Ratio equals or approximates 1.0 vs if it’s above 2.0, what do they mean with significance?
1.0 = there is no significance
2.0 = there is significance (one group did better than the other group/stronger your results are)
When the ANOVA is found to be significant, with there being differences between groups, it’s not clear which one of the groups is significantly different from which others; what type of testing is then required?
Post-Hoc Testing
Which one of the post-hoc tests (Scheffe & Tukey vs Fisher’s LSD) provides the least protection from a Type II (2) error, and which offers the most protection?
Least protection: Scheffe & Tukey
Most protection: Fisher’s LSD
Which one of the post-hoc tests (Scheffe & Tukey vs Fisher’s LSD) provides the least protection from a Type I (1) error, and which offers the most protection?
Least protection: Fisher’s LSD
Most protection: Scheffe & Tukey
What’s the downside of Scheffe & Tukey protecting you from Type 1 Errors?
The chance of a Type II error increases
What test do you use when groups are being compared on 2 independent variables (e.g., sex & treatment)
Two-way ANOVA
What test has the advantage of permitting analysis of each independent variable’s main effects (significance) but also allows analysis of interaction effects?
Two-way ANOVA
When running a two-way ANOVA, why are 3 F-ratios obtained?
one for each of the 2 independent variables and then another for the interaction effect
How do you know if there was a main effect of a two-way ANOVA when there’s a table?
Add up the totals of each column and see if they are the same or different numbers when comparing the totals. If they are different, then that means there was a main effect; if they are the same, there was no main effect
Easy way to see if there were interaction effects with a two-way ANOVA table
Add up two squares that are diagonal from one another, then add up two other squares diagonal from each other; if the sum of each pair of diagonals is different, you can conclude there are interaction effects
When do you use trend analysis as a follow-up to ANOVA, with linear or non-linear data?
To analyze non-linear data
Statistics that depict relationships between variables (X & Y) are termed ________, while statistics that predict are termed _________ or _________
relationships = correlations
predict = regressions or analyses