Workshop 4 - Graphs Flashcards
Absolute frequency
The number of times you have observed that value (count)
Relative frequency
the number of times you have observed a value, expressed as a percentage.
Valid frequency
If someone leaves a question blank, you can calculate the relative frequency compared to everyone who answered that question.
Cumulative frequency
To find the cumulative relative frequency you add the relative frequencies of a group to the percentages of the previous groups.
Bar graph
Best be used if there are not too man groups + the groups all have sufficiently high frequencies. Variables on the nominal or ordinal level. The bars have to be separate.
Clustered bar graph
Two bar graphs combined into one. Nominal or ordinal level.
Histogram
- Divide your data into fixed groups
- You determine how many groups you want
- The bards are stacked against each other to show that the groups are connected
Interval / ratio level
Pie chart
Nominal or ordinal
Can see the ratios between groups less well than bar chart.
Line graph
- You put time on the horizontal axis (X-axis)
- You put the variable of interest on the vertical axis (Y-axis)
- Shows the progress of a variable over time.
Interval / ratio level
Box plot
Looks at the centre of your data and variation Three parts: - middle bar (mean) - box (Q1 -> Q3) - lines (min and max)