presentation of quantitative data Flashcards
(20 cards)
What is the purpose of summarising data in a table?
To represent data in a summary form using descriptive statistics, making it easier to interpret and draw conclusions.
What is the difference between raw scores and descriptive statistics in tables?
Raw scores are the original data, while descriptive statistics are calculated values (like mean and standard deviation) that summarize and describe the data.
What does a higher standard deviation indicate about a data set?
A higher standard deviation suggests a larger spread of scores, meaning participants’ results varied more widely from the mean.
What is the main advantage of using a bar chart?
Bar charts visually display differences in mean values between categories, making comparisons easy.
When should you use a bar chart?
Use a bar chart when data is divided into discrete categories, such as different experimental conditions.
How are categories and frequency represented in a bar chart?
Categories are on the horizontal x-axis, and frequency or amount is on the vertical y-axis (height of the bar).
What does it mean when bars are separated in a bar chart?
It indicates that the data is discrete and the categories are separate.
What type of data is best represented by a histogram?
Continuous data, where the x-axis shows intervals of a single category and bars touch each other.
How does a histogram differ from a bar chart?
In a histogram, bars touch each other (continuous data); in a bar chart, bars are separated (discrete data).
What does the y-axis represent in a histogram?
The frequency (number of people or items) within each interval.
What happens if there is zero frequency for an interval in a histogram?
The interval remains on the x-axis but without a bar.
What do scattergrams show?
Scattergrams show associations between two co-variables, not differences.
How are variables plotted in a scattergram?
Each co-variable is plotted on one axis (x or y), and each point represents a pair of values.
What is a normal distribution?
A symmetrical, bell-shaped curve where most scores cluster around the mean, median, and mode, with few at the extremes.
Where are the mean, median, and mode located in a normal distribution?
They all occupy the same midpoint of the curve.
What is a skewed distribution?
A distribution that leans to one side, with scores concentrated away from the center.
What is a positive skew?
Most scores are on the left with a long tail on the right; mean is pulled to the right.
What is a negative skew?
Most scores are on the right with a long tail on the left; mean is pulled to the left.
How do extreme scores affect the mean in a skewed distribution?
Extreme scores pull the mean towards the tail of the distribution.
What is the order of mean, median, and mode in a positive skew?
Mode is highest, then median, then mean (mean is pulled right).
