Data Analysis In Quantitative Studies Flashcards
What are levels of measurement (or types of data) from least complexity to most?
Nominal level, ordinal level, interval level, ratio level
What is nominal level?
- provides info about difference, but not much more
- used to name, identify, or classify into categories
What is ordinal level?
- shows direction of difference, but we don’t know amount of difference
- numbers indicate rank or order
- allows for “greater than” or “less than”
Ex) podium: know 1st, 2nd, 3rd but not know how much won by
What is interval level?
- intervals or distances between numbers are known, but it’s not known how far any of the numbers are from zero
- equality of units, but no true zero
Ex) Celsius temp scale, know dif +1 to +2 same as +21 to +22
Can go below 0
What is ratio level?
- each number can be thought of as a distance measured from zero
- there is an absolute zero point, represents absence of the variable being measured
Ex) weight
What is nominal and ordinal levels?
Non-parametric data
What is the relationship between levels?
Each level has additional characteristic, and contains all the characteristics of the previous one
What is interval and ratio levels?
Parametric data
What is statistics?
Objective means of interpreting data
What 2 things does statistics inform us?
Reliability and meaningfulness
What are the most fundamental components of most statistical techniques?
Central tendency and variability (describe data set)
What is central tendency?
- single score that best represents all scores for a group of individuals
3 ways to measure central tendency?
Mean
Median: number occurring at midpoint of series
Mode: most frequently occurring number
What is variability?
Best estimate of the spread of scores
How to measure variability?
1) variance
2) standard deviation (square root of variance)