Statistics and correlation How might we use stats in psych?
-
Upload
marlene-thornton -
Category
Documents
-
view
220 -
download
3
Transcript of Statistics and correlation How might we use stats in psych?
Statistics
• How do we describe data?-Gather raw data-Frequency Distribution= number or
frequency of a behavior.- X-axis=data you are graphing- Y-axis= represents frequency
Histograms= Bar graphs
Measures of Central tendency
• Mode- The score that occurs most often
• Why Use?
• Median-the middle score
• How do we calculate median?
Calculating Mean….
• Mean-The average of all scores
How do we calculate mean?
How can mean be distorted?
Outliers= example
Demo- Positive and negative skew
Measures of Variation
• The Wechsler IQ scale
• Range- gap between high and low scores
• Standard deviation- measures the degree to which scores deviate from one another
• EX: IQ
Correlation-Handout
Correlation Coefficient A statistical measure that indicates how well either
factor predicts the other
Correlation coefficient
Indicates directionof relationship
(positive or negative)
Indicates strengthof relationship(0.00 to 1.00)
r = +.37
Understanding Correlations• NOT Cause and effect
• Frosted Flakes prevents cancer, oatmeal causes cancer ( Good News Survey)
• TV watching is linked to childhood obesity
Illusory Correlation
• The perception that a relationship exists between two variables when no relationship is present.
• Ex:
Correlation Research
• Advantages:Can examine a relationship between two variablesSaves $ and timeCan allow one to make predictionsAllows use of preexisting data
Disadvantages:Cant establish CAUSE & EFFECTProne to inaccurate reporting ( survey)Confounding variablesCant manipulate variables
Advantages & Disadvantages: Experiment• Advantages:• CAN establish cause and effect• Can actively manipulate variables
via operationalization of variables• Can use double blind procedure• Can distinguish between real and
placebo effects• Can be replicated
Disadvantages:
• Experiments may be artificial or contrived
• Hard to establish controls, eliminate confounding variables
• Probability of bias
• $ and time consuming
Others Methods of Research:
• Case History= A biographical review of patients relevant history.
• Advantages:• - In depth info
- Rare Phenomena or unusual cases
- Preexisting cases don’t involve ethics
- Time and $ Factors
Case History:
- Disadvantages:- Can’t generalize results
- Inaccurate reporting
- no cause and effect
Naturalistic Observation:
Naturalistic Observation observing and recording behavior in
naturally occurring situations
• Advantages: natural setting
• Disadvantages: cant generalize, variables are not controlled
Description
Survey the self-reported attitudes or behaviors
of people representative, random sample of
people
Limitation:
Intentions are not always translated into action