Key Science Skills for AOS 1 UNIT4 Flashcards
Within Subjects Design
Both.
Participants experience one condition (control group) and the other condition (experimental group)
Between Subjects Design
One or the other.
Participants are allocated to either the controlled group or the experimental group
Mixed Subjects Design
Before and after.
Between subjects design and within subject design -> everyone measured before experiment and after
Central Tendency
Mean
Median
Mode
Mean
Sum of all the values divided by the number of values
To get an average
Limitation: outliers the average will change
Median
The middle number in an ordered set of data
Limitation: there might be some really low values and some really high values, outliers effecting how central the median is
Mode
Most frequent value
Limitations: could be more than one mode
Measures of variability
Range
Interquartile range
Standard deviation
Variance
Range
The difference between the highest and lowest values
Interquartile Range
The range of the middle half of a distribution
Variance
Average of squared distances from mean
Personal Errors
Experimenter mistakes
Random Errors
Different every time
Repeatability detects random errors
Systematic Errors
The same error across all samples have the same error
Reproducibility detects systematic errors
Validity
Extent to which psychology tools and investigations truly support their findings or conclusions
Measures what it aims to measure
(DV measures the effect of the IV)
