Variables at Work
This is the larger group of cases that a researcher wants to understand.
What is a population?
This level of measurement is used for categories with no meaningful order, such as eye color or college major.
What is nominal measurement?
This graph displays a frequency distribution for continuous data using bars that touch.
What is a histogram?
This measure of central tendency is the arithmetic average of a set of scores.
What is the mean?
This standard score tells how far a raw score is from the mean in standard-deviation units.
What is a z score?
This is a smaller group selected from a population to participate in a study.
What is a sample?
Response options such as never, rarely, sometimes, and often are measured at this level.
What is ordinal measurement?
This graph is appropriate for nominal or categorical data and has spaces between its bars.
What is a bar graph?
This measure of central tendency is found by arranging scores in order and locating the middle score.
What is the median?
A raw score with a positive deviation score is located on this side of the mean.
What is above the mean?
The outcome variable in a study is also called this type of variable.
What is the dependent variable?
This level of measurement has a meaningful zero and allows meaningful multiplication and division. Distance and elapsed time are examples.
What is ratio measurement?
A distribution with a long tail extending to the right is described this way.
What is positively skewed, or skewed right?
This is the score or interval with the highest frequency.
What is the mode?
After all raw scores are transformed into z scores, the mean of the resulting distribution is this value.
What is zero?
Unlike a correlational study, this research design can support cause-and-effect conclusions because the researcher manipulates an independent variable.
What is an experimental design?
These values answer the question “How many?” and cannot take fractional values.
What are discrete numbers?
This type of distribution has two or more distinct scores or intervals with the highest frequencies.
What is a multimodal distribution?
This measure of variability represents the distance covered by the middle 50% of scores.
What is the interquartile range?
After all raw scores are transformed into z scores, the standard deviation of the resulting distribution is this value.
What is one?
In this design, participants are classified into groups using a characteristic they already possess, rather than random assignment.
What is a quasi-experimental design?
These numbers can take fractional values, such as 5.5 miles or 2.75 hours.
What are continuous numbers?
This type of frequency distribution is most appropriate when a variable has a limited number of possible values, such as number of siblings.
What is an ungrouped frequency distribution?
A data set includes one extreme income that is much larger than every other income. This measure of central tendency is usually the best choice for describing a typical income.
What is the median?
In a normal distribution, approximately what percentage of scores falls below z=−0.50.
What is 30.85%?