Research Methods Unit 2 Flashcards
What is a research/alternative hypothesis?
The belief that there is a difference due to the treatment/manipulated variable within an experiment (H1)
What is a null hypothesis?
A null hypothesis is the belief that there will be no difference when the treatment or manipulated variable is applied during an experiment.
What is confidence interval testing?
Confidence interval testing is an alternative to null hypothesis based on how certain the researcher is that their hypothesis is correct
What is a type ll error?
A type ll error (the less egrigious of the two) is the incorrect belief that the null hypothesis is false and that there is not a difference when the manipulation is applied in an experiment (less egrigious because it just means the experiment failed to notice a correlation and is ammendable by replication)
What is a type l error?
A type l error is the false assumption that the null hypothesis is false when it is actually true (falsely assuming there is a correlation where there is not could be the root of the replication problem.)
What is an example of a null hypothesis?
When looking at normal and abnormal faces the time starting will be no differnt
What is an example of a research hypothesis?
Between looking at normal and abnormal faces the participant will spend more time looking at the abnormal face.
What is a type l error example?
There is a significant difference between the lookings time (where there is in fact no significant diffrence)
What is a type ll error example?
There is no significant difference between the looking times (when there is in fact a significant difference)
Univariate Analysis
The analysis of one variable across mutiple cases that make up a data set
Bivariate analysis
The analysis of two variables across mutiple cases which make up a data set
Multivariate analysis
The analysis of three or more variables across mutiple cases that make up a data set
What are the three characteristics of a variable?
- The distribution of the variable
- The measure of center
- The spread/disposition of the set
Central tendency
The estimate of the center of distribution of values
Mean
The average of all the numbers within a distribution (is flawed because in including all the values it tends to skew high/low depending on the outliers)
Median
The middle value of a distribution (the most resistant to skewing bias becaause it is a location within the set rather than a sum of values)
Mode
The most often occuring values within a set (there can be multiple if a bimodal or multimodal graph)
What are the steps to find the mean?
❶ Add up all the scores. That is, figure E X.
❷ Divide this sum by the number of scores. That is, divide g X by N.
What is the means equation?
M = E X/N
What are the steps to find the median
❶ Line up all the scores from lowest to highest.
❷ Figure how many scores there are to the middle score
❸ Count up to the middle score or scores. If you have one middle score, this
is the median. If you have two middle scores, the median is the average (the
mean) of these two scores
How to find the mode?
- line up values from low to high
- count how many times each value appears
- (if there are multiple numbers that occur the same amount you have multiple modes)
Dispursion
The spread of values around the central tendency
Range
Subtracting the lowest from the highest value of a data set to get the range (limited due to only considering two variables and not the frequency of occurance +paired w/ the median)
Variance
A measure of how spread out a
set of scores are; average of the squared
deviations from the mean.