Chapter 4 Flashcards
What is a nominal scale?
What is a ordinal scale?
What is a interval scale?
What is a ratio scale?
Nominal scale: Assign numbers to represent groups or categories of information- Serve as labels only
Ex- eye color, gender
Ordinal scale: order, rank
Ex- Small, medium, large
Interval scale: no absolute zero, intervals between values are equal
Ex- temperature, mean, Standard deviation
Ratio scale: Absolute point of absence= 0
Ex- weight, height
Are the most basic scores calculated from a psychological tests.
What type of score is this.
Raw scores
A previously tested group of individuals.
What type of group is this?
Norm group
What is standard deviation?
On average, how far does the score deviate from the mean
Difference between positively and negatively skewed distributions?
2pts
Positively skewed distributions: right skewed/tail, high point is left
Negatively skewed distributions: left skewed/tail, high point is right
Where is the mean, median and mode on a positive skewed, negative skewed, symmetrical distribution?
3pts
Positive skew: mode median, mean
Negative skew: Mean, median, mode
Symmetrical distribution: mean, median, mode (all the same value)
What is the median, mode, outliers and measures of variability?
4pts
Median: Is the middle score in a group of scores (must be ordered first)
Mode: Most common score in distribution
Outliers: Values that are significantly higher or lower than most of the values
Measures of variability: Describe a set of scores in numerical form
Measures the linear association between two variables, or sets of test scores, that have been measured on interval or ratio scales.
What concept is this ?
What does 0 and 1 mean?
2pts
Pearson product moment correlation coefficient
Correlation of: 0 (scattered) to 1 (one straight line)
What is the x and y axis of a histogram?
Y axis: frequency
X axis: scores/values
What is the standard deviation and mean for the following:
- GRE
- IQ
- SAT
- T-scores
- Z-scores
5pts
GRE: mean is 500 and SD is 100
IQ: Mean is 100 and SD is 15
SAT: Mean is 500 and SD 100
T-scores: Mean is 50 and SD 10
Z-scores: Mean is 0 and SD is 1
A distribution that falls at or below a given raw score or is the percentage of scores in a distribution that falls below a given raw score.
What is this? What does it tell you? What do they range from?
Give an example.
Percentile
Example:
Lets say you take a test, and 100 people took the same test. Your percentile tells you how you did compared to those people.
If you’re in the 80th percentile, it means you scored better than 80 out of those 100 people.
Percentiles range from 1 to 99, with higher numbers meaning you did better.
Are a standard score scale with nine points that allows us to describe a distribution in words instead of numbers.
What concept is this?
Stanines
What are the values/percentages for the SD’s ranging from -/+ 0-3 for a normal distribution?
- Between SD -/+ 2 & 3= 2.1%
- Between SD -/+ 1 & 2= 13.6%
- Between SD -/+ 0 & 1 = 34.1%
EACH SIDE- NEGATIVE AND POSITIVE
Is a value that helps us understand the middle of a distribution or set of scores.
What type of measure is this?
Measure of central tendency
