Terms
A relationship between variables in which one variable increases as the other variable also increases
Positive correlation
A statistical test used to determine the significance of the difference between two means (groups)
T-test
You want the F-statistic to be ______ and the p-value to be _______
big, small
Chi-square step 1
Determine the alpha value and df
Franlkin, Janoff-Bulman, and Roberts (1990) looked at the long-term impact of divorce on college students’ level of optimism. They compared students from divorced families and students from intact families.
t-test (you are comparing the mean scores of the 2 groups)
A method of finding the best model for a linear relationship between the explanatory (IV) and response (DV) variable.
Process of drawing a line to represent an association between two variables on a scatter plot
Linear Regression
A statistical test used to analyze data from an experimental design with one independent variable that has 3 or more groups (levels).
1 IV
1 DV
One-way ANOVA
P-value linked to the computed t-score must be _______ than alpha (0.05) for the results to be significant
less
Chi-square step 2
Use the table to find the χ2 critical value
Davey, Startup, Zara, MacDonald, and Field (2013) were interested in the role of mood on the degree of compulsive checking in which a person engaged. Three groups of 10 participants each listened to music designed to induce a positive, negative, or neutral mood. They were then asked to “list as many things around your home that you should check for safety or security reasons before you go away for three weeks.” The dependent variable was the number of things listed.
One-Way ANOVA (you are comparing the mean scores of the 3 groups)
r^2: the variation in Y that is explained by X
r^2 is rxr
example: a correlation with 0.7 explained 49% (0.7 x 0.7 = 0.49) of the variance in the outcome variable
Regression coefficient
Inferential statistics test for discrete (categorical) data
Chi-Square
The probability of incorrectly rejecting the null
P-value (Type 1 Error)
Chi-square step 3
Create a table showing the expected and observed data values
Mann et al. (2016) investigated whether sensation seeking was related to delinquency in adolescence. A large sample of adolescent twins (N = 549 pairs) completed a series of surveys. As originally hypothesized, they found that higher levels of sensation seeking were related to higher delinquency.
Correlation (you are examining the relationship between 2 variables)
total number of categories
k
Used to compare the observed data with theoretically predicted data
Chi-Square goodness of fit test
Mean of group 1 - mean of group 2/ standard deviation of both groups
While technically infinite, the range is typically -4.00 to +4.00
T-score equation
Chi-square steps 4 & 5
4) Use table to calculate χ2
5) Compare χ2 to critical χ2
White (2001) was interested in the effect of two different types of exercise programs for improving time to run a marathon. He was one of the first researchers to evaluate how each type of exercise program effected the running times for participants of both normal and obese body types.
Two-way ANOVA (you are comparing the mean scores of the 4 groups)
The value used for determining the significance of the difference between means is the
p-value
Both independent variables are between subjects
Factorial design (two-way)
Equation for χ2
χ2 = (O-E/E)^2 + (O-E/E)^2
Chi-square step 6
State whether observed data values are significantly different from chance
In a recent study on environmental and biological influences on ADHD, Bogaert (2006) asked 944 men with ADHD whether they had an older brother or not, and found that the proportion of participants with an older brother was significantly greater than what would be expected due to chance.
Chi-square (you are evaluating whether sample data are different from hypothetical data)