Descriptive statistics Flashcards
Data
The measurements collected from an experiment to illustrate a trend or lack thereof that the IV has on DV
Forms of data can be in
Primary or secondary
Quantitative or qualitative
Discrete or continuous
Raw or processed
Primary data
Data collected within each condition from an experiment by a researcher
Secondary data
Data which already exists and is collected by researchers to analyse
Quantitive data
Measurements taken in the form of numbers
Qualitative data
Measurements taken in the form of words, descriptions, observations, pictures etc
Not limited by a choice or scale and can not be put into pre set categories
Can qualitative data be processed into quantitate data?
Yes then can be analysed
Discrete data
Values that can only fit in a scale/ categories of fixed and specific values, such as blood type
And there is no in between such as number of people, number of words recounted etc (cannot have half of a word for example)
Continuous data
Values that can be counted in a scale of continuous values so can be in between intervals and exist as any value
Such as length, weight and height
Raw data
Data collected straight from the experiment which has not been processed
Such as pre making a table for an experiment and inputting values collected
Processed data
Data which has been put into graphs and drawing conclusions from it etc
Raw data tables
Made before an experiment to input values which will be collected in the experiment
No analysis
Raw data table for repeated measures design
All as 1 big column
Participant number down the first column
Then the other columns for scores taken from each condition completed
To show every participant took part in the same condition
Raw data for matched participant/ independent measures design
1 table per condition to show each participant took part only once in only 1 condition so no repeating
Descriptive statistics
Calculations made straight from raw data collected to sum up and present findings
Or drawing graphs
Measures of central tendency
Ways of determining the average of typical score in a set of data :
Mean
Mode
Median
How to calculate mean
Total of all scores
—————————————
How many scores there are
Advantages of mean
All data is included when calculated so doesn’t ignore any scores
Disadvantages of mean
An outlier score would skew the mean calculated so wouldn’t represent most of the scores
How to calculate median
Put in order smallest to largest
Find middle value
If there are 2 middle values then find midpoint of those
Advantages of median
Not affected by an outlier score so not skewed
Disadvantages of median
Not helpful if there are not enough values
Not take into account the precise other values so not use all data
How to calculate the mode
Most common score
Can be more than 1 or none at all
Advantages of mode
Can be used for qualitative data
Easy to calculate
Not affected by outlier score
