Lecture 5 Chapter 5 Selecting and Interpreting Inferential Statistics Flashcards
If the P value is less than or equal to the alpha value then you ______ the null hypothesis?
Reject
If the P value is less than the alpha value then you ______ the null hypothesis?
Fail to reject the null or accept the null
What does the p value indicate?
The percent of how much of your results are due to coincidence/randomness
What do we use to decide whether to accept or reject the null hypothesis? Two things?
P-value
Alpha Level
What is a type 1 error ?
rejecting a true null hypothesis (when p value is greater than Alpha)
What is a type 2 error?
-Accepting a false when it is statistically significant
-Accepting null hypothesis when we shouldn’t
Why are type 1 and 2 errors related?
As the probability of making a Type I error increases, the probability of making a Type II error decreases, and vice-versa
What value determines the probability of making a Type I error?
Alpha
If the alpha is set at 0.01, the researcher how likely to commit Type I errors?
1% of the time
If the alpha is set at 0.05, the researcher how likely to commit Type I errors?
5% of the time
If the alpha is set at 0.10, the researcher how likely to commit Type I errors
10% of the time
Researchers don’t like making _____ errors, so they tend to have very low alpha values
Type 1 errors
The alpha level describes the_________researchers place in their research results
level of confidence
What are the three steps to seeing if you have a statistically significant results?
ASSOCIATION QUESTION
1) First, determine if you have a statistically significant association (by comparing the computed p-value to the selected alpha-level)
2) Second, determine the effect size of the association (see Table 5.5).
3) Third, determine the direction of the association using the sign in front of the correlation coefficients.
What are the three steps to seeing if you have a statistically significant results?
DIFFERENCE QUESTION
1) First, determine if you have a statistically significant difference (by comparing the computed p-value to the selected alpha-level)
2) Second, determine the direction of the difference or the direction of effect (by identifying the group with the highest mean or mean rank or frequency)
3) Examine the clinical or practical significance of the difference
What are the upper and lower limits when we reject the null hypothesis?
both positive
both negative
What are the upper and lower limits when we fail to reject the null hypothesis?
One negative and one positive
When Levene’s test is significant do we assume equal variance or do not assume equal variance?
When Levene’s test is significant we do not assume equality of variance
When Levene’s test is NOT significant do we assume equal variance or do not assume equal variance?
A non-significant p value of levene’s test show that the variances are indeed equal and there is no difference in variances of both groups
TRUE/FALSE
The larger the sample, the more likely the results will be statistically
significant
True
Any association or difference can be statistically significant if sample sizes are ______
Large enough
The bigger the _______ it is less likely our research results would be due to chance
sample
What does statistical power give us? Three things
-Ability to reject the null hypothesis when we really should
* Ability to find a true difference or association that actually exists
* Ability to claim we have statistically significant results
How do we increase power?
two options
Have a low alpha value
Have a large sample size
