Name that test
Name the most appropriate test for the following research hypothesis:
"There will be a significant difference between males and females in performance on a standardized achievement test."
Independent samples t-test
My hypothesis is the reverse of the research hypothesis, what is my hypothesis?
Null hypothesis
In a simple linear regression, the _________ variable is the predicted outcome variable.
Dependent Variable
In regression tests, I predict Y^ when X1 is equal to 0.
What am I?
The Intercept or the Constant
In making a conclusion from your statistical test, when the H0 (null hypothesis) is FALSE, you should...
Reject the Null
Name the appropriate test for the following research objective:
A researcher wishes to figure out whether there is a relationship between grade point average (GPA) and the scores on a reading-comprehension test pf 15 first-year students.
Pearson's correlation
A researcher failed to reject the null hypothesis that men and women differed in exam performance. What test did they run and what was the result of their test?
Hint: (significant/non-significant)
Independent samples t-test; Their test was non-significant.
Use the regression formula below to identify which part would represent the raw score of the predictor variable.
Y’ = a + β1(X1)
X1
In a study on poverty and health, annual family income ranged from $40,000 - $150,000. The researcher dummy-coded this variable into two categories represented by "0" and "1". Please provide a dummy coding scheme that split the family income variable down the middle.
$40,000 - $95,000 = 0
$96,000 - $150,000 = 1
In making a conclusion from your statistical test, when the H0 (null hypothesis) is TRUE, you should...
Fail to Reject the Null
Name the appropriate test for the following research question:
"Does the recidivism rate of juvenile offenders who are provided with father figures differ from those without father figures?
Independent sample t-test
Provide the null and research hypothesis (in symbols):
H0: There will be no relationship between income and life satisfaction.
H1: There will be a relationship between income and life satisfaction.
H0: r = 0
H1: r ≠ 0
50 women are asked to give a rating on their confidence level before and after visiting the hair salon.
IV: Visits to the hair salon
There was not significant difference in depressive symptoms for young adults on medication (M = 2.15, SD = 0.68) and young adults not on medication (M = 2.15, SD = 0.68); t(8) = 1.92, p = 0.39.
How did the researcher determine that this finding was non-significant?
The p-value was equal to 0.39, it is greater than 0.05.
What kind of error is this?
"Rejecting the Null hypothesis when it is true"
TYPE I ERROR
Name the appropriate test for the following research objective:
Politicians contact a team of researchers to help predict voting behaviors for the upcoming election using the prior voting record of Fulton County residents.
Simple linear regression
Provide the null and research hypothesis (in words):
H0: β1 = 0
H1: β1 ≠ 0
H0: There is no significant linear relationship between the predictor and the dependent variable.
H1: There is a significant linear relationship between the predictor and the dependent variable.
Name the independent (also name the levels) and dependent variables in the following research question:
A researcher is interested in finding out whether intensity of electric shock will affect the time required to solve a set of difficult problems. Eighteen subjects are randomly assigned to the three experimental conditions of “Low Shock,” “Medium Shock,” and “High Shock.” The total time (in minutes) required to solve all the problems is the measure recorded for each subject.
IV: Intensity of electric shock
Level 1: Low Shock
Level 2: Medium Shock
Level 3: High Shock
DV: Time required to solve a set of difficult problems
Interpret the statistic below in narrative format:
r = -0.75
Hint: state the strength and direction
Pearson's r indicates that there was a strong, negative correlation.
What kind of error is this?
"Failing to reject the null hypothesis when it is false"
TYPE II ERROR
Name the appropriate test for the following research objective:
A researcher designed an experiment to test the effect of drug X on eating behavior. The amount of food eaten by a group of rats in a one-week period, prior to ingesting drug X, was recorded. The rats were then given drug X, and the amount of food eaten in a one-week period was again recorded. The following amounts of food in grams were eaten during the “before” and “after” conditions.
Paired Samples t-test
To reduce the amount of subjectivity that exists when researchers interpret their results, they use a decision rule that specifies the conditions under which the researchers will decide to refute or support the hypotheses they are testing. What is this decision rule called and at what level do we consider results significant or non-significant?
Level of significance; p ≤ 0.05
You are given the following IVs and DVs. Please form a research question using multiple linear regression with the following IVs and DVs.
IV: Family income, gentle parenting, and attachment style
DV: Help-seeking behaviors
"How will family income, gentle parenting style, and attachment style predict youth's help seeking behaviors?"
OR
"What is the likelihood that family income, gentle parenting style, and attachment style will predict youth help seeking behaviors?"
Write an APA-style results statement for a standard multiple regression:
IVs: Annual family income, gentle parenting style, and attachment style
DV: Help-seeking behaviors
F = 32.39
df regression = 4
df residual = 95
p <0.05
R2: 0.08
Annual family income, gentle parenting style, and attachment style significantly predict help-seeking behaviors, F(4,95) = 32.39, p<0.05, R2 = 0.08. All three variables added significantly to the prediction, p<0.05.
Why do we use a probability value when conducting statistical tests?
It is a standard value for what we allocate to error or chance/probability