Presentation of quantitative data Flashcards
Tables
-Raw scores displayed in columns and rows
-A summary paragraph beneath the table explains the findings and draws conclusions
Bar charts
-Categories are usually placed along the x-axis and frequency on the y-axis
-The height of each column represents the frequency of that item
Histogram
Bars touch each other- data is continuous rather than discrete. There is a true zero
Scattergram
-Used for correlational analysis. Each dot represents one pair of related data. Illustrates strength and direction of correlation
-The data on both axes must be continuous
Normal distribution
-Symmetrical, bell-shaped curve. Most items are in the middle area of the curve with very few at the extreme ends
-The mean, median and mode all occupy the same mid-point of the curve
Skewed distribution
Distributions that lean to one side or the other because most items are either at the lower or upper end of thee distribution
Negative skew
-Most of the distribution is concentrated towards the right of the graph, resulting in a long tail on the left.
-E.g. a very easy test in which most people get high marks would produce a negative skew
-The mode. Is the highest point of the peak, the median comes next, and the mean is dragged across to the left (if scores are arranged from lowest to highest)
Positive skew
-Most of the distribution is concentrated towards the left of the graph, resulting in a long tail on the left
-E.g. a vey difficult test in which most people get low marks would produce a positive skew
-The mode is the highest point of the peak, the median comes next, and the mean is dragged across to the right (if scores are arranged from lowest to highest)