Validity & Variability
What is external validity?
How generalizable the study is to
other places, time, or people
Name a reason we learned about why we should not always use experiments.
A) Not always possible
B) Not always ethical
C) Not always generalizable/valid
What is the mode of the following dataset?
1, 2, 2, 2, 3, 5, 8, 8, 12, 21
2
What inferential statistic compares the means of two groups?
An independent samples t-test
What are the three requirements for casuality?
Temporal Order
Eliminate Rival Explination
What is variability?
How spread out the data is.
How does an experiment ensure temporal order?
By manipulating the independent variable
What is the median of the following data set?
1, 2, 3, 4, 4, 6, 7, 8, 8, 9
5
What inferential statistic tests whether there is a relationship between two variables?
Correlation
What does it mean for a variable to have temporal order?
You can prove the IV happens prior to the DV
The measure of how far away data points tend to be from the mean is called the?
Standard deviation (Brandon Explain Range/Frequency for exam)
What does an experiment feature that a survey does not?
A manipulated IV
What is a median?
The middle point of a data set
We conducted a correlation analysis and discovered that our sig value was .02, is our relationship significant? Why?
Yes because p<.05
Can cross sectional surveys rule out rival explanations?
NO
When each person has a known chance/probability of being selected for the sample from the population you have a ________.
Probability Sample (Brandon explain Non-probability sampling for the exam)
Imagine the following hypothesis was tested in an experiment: Teaching with slides will result in higher student grades than teaching without slides.
What is the treatment group? What is the control group?
Treatment: Instructor teaches with slides.
Control: Instructor teaches without slides.
On nominal data sets that don't have mathematical values.
What statistical test would someone run if they wanted to compare whether watching Drunk Driving PSAs (or not) results in lower willingness to drink and drive?
An independent samples t-test
What two types of research did we learn about that can prove temporal order?
Longitudinal surveys and experiments
We are researching dating behaviors of people over the age of 18-years-old in Lawrence, KS. We go to Instagram and find everyone who lists Lawrence, KS as the location of their most recent post. Then, we send digital questionnaires to a random 1,000 of the people who do so.
What is the population?
What is the sampling frame?
What is the sample?
1. People in Lawrence over 18
2. People on Instagram who list Lawrence as their most recent location
3. Random 1000 people from the sampling frame
What is the method in which researchers create equivalent conditions that eliminate selection bias and reduces rival explanations?
Random Assignment
What level of central tendency would you use for the following dataset and why?
1, 2, 2, 3, 4, 7, 10, 11, 6, 7, 12, 4, 7, 99, 1, 2
You would use the median because there is an outlier.
A researcher wants is testing the following hypothesis: Students who skip class have higher grades.
Their SPSS output gives them the following values
r=-.78
sig= .001
N = 35
Is their hypothesis supported?
No, because the direction of the relationship is in the opposite direction of the hypothesis.
Which type of research did we learn about that can prove casuality?
Experiments