Graphs and tables Flashcards
Features of a bar graph
Title - operationalises both variables
Bars with accurate data points with a gap between
STARTS AT 0 on the y axis
Categories on the x axis
When are bar graphs used?
For discrete data that fits into 2/more categories
That is usually nominal, as the height of the bars represents the frequency (headcount) of scors for each category
Features of a histogram
Frequency density on y axis shows relative proportion of scores achieved in each interval
Title - operationalise both variable
Touching bars for each interval that is labelled on x axis
So x axis shows continuous data set
When are histograms used?
For continuous data that has been divided into potentially uneven groups
Eg interval level data
How is the frequency density for each bar calculated?
Frequency/ class width
FOR EACH INTERVAL
What does the area of each bar represent in a histogram?
THE FREQUENCY OF SCORES ACHIEVED FOR EACH INTERVAL
When do we need to estimate the mean for grouped data?
Continuous data is grouped into categories
And we have the frequency that scored within this category but dont know their exact score so we do not know the mean of this data
How to estimate the mean for grouped data
Find midpoint of each category
Multiply midpoint and frequency together
Find total of midpoint x frequency
Divide this by total number of participants
Frequency tables
A tally chart that shows how often a value in the category occurs
How to construct a frequency table
Categories in one column
The frequency in next column for each category to show when it occurs
Pie chart
use percentages to represent segments of a circle as the values associated with data groups
How to construct a pie chart
Find percentage that represents the frequency of the group
Find the segment of this percentage in a circle eg 360 degrees
Line graph
Plotting continuous data (obtained from DV) on the y axis to see how it changes with IV on the x axis
Over time
CONNECTED BY LINE
Scatter graph
Used to show correlation between 2 variables
Raw data
Data collected by researchers straight from an experiment that hasnt been analysed in any way
