Fundamental Statistics Flashcards
“process of administering a test to collect information”
measurement
“process of placing a value judgement on the measurement - involves analyzing scores and using statistics to enhance interpretation”
evaluation
4 steps in measurement and evaluation?
- Collect data and create initial data set
- Check for errors and unusual scores
- Select appropriate analyses and perform calculations
- Interpret results
Common problems?
- data recording/entry errors
- outliers
- missing data
how can you reduce errors?
- work in pairs to enter data (reader, recorder, repeater!!)
- use numeric keypad to minimize inputting errors
“indicates the point around which scores are concentrated - a single score that best represents all of the scores”
central tendancy
“indicates how data points are spread around the center”
variability
“an estimate of the variability between the individual scores and the central tendency scores”
variability
what are the three measures of central tendency?
- mean
- median
- mode
“average distribution of scores - most commonly reported measure of central tendency”
mean
“midpoint of a distribution - 50% of scores lie above and 50% lie below”
median
“most frequently occurring score in a distribution - useful for highlighting clusters of data”
mode
What is step #1 when getting a median value?
organizing the numbers from smallest to largest
what would it mean to have bimodal data?
1,2,2,2,4,5,6,6,6,7,9
2 and 6 are the modes
In a good data set, where will the mean, median, and mode all be?
right around the same point, with 50% data above and 50% data below
Left-skewed data is said to be _____ skewed, while right-skewed data is said to be ____ skewed
negatively ; positively
left - starts low and goes up
right - starts high and decreases
what are two measures of variability?
range and standard deviation
“simplest measure of variability”
range
what is the formula for range? why is it unstable?
max score - min score
unstable cause it only depends on 2 scores
“amount that all scores vary from the mean - more commonly reported”
standard deviaiton
what is a good standard deviation score?
min value = 0 - the larger the value, the greater the variability
Almost all values in normally distributed data will fall within at least __ SD of the mean; 68% will fall within __ SD and 95% will fall within ___ SD and 99% will fall within __ SD
3
68% = 1
95% = 2
99% = 3
Name the type of data analysis:
-determine differences between 2 mean scores
t-test
Name the type of data analysis:
-determine differences between multiple mean scores
ANOVA
Name the type of data analysis:
-determine relationships between variables
correlation
Name the type of data analysis:
-prediction equations
regression analysis
ON EXAM What are the values for the following correlation coefficient (r)? 0-0.25 = 0.26-0.49 = 0.5-0.69 = 0.7-0.89 = 0.9-1.0 =
0-0.25 = little, if any
- 26-0.49 = low
- 5-0.69 = moderate
- 7-0.89 = high
- 9-1.0 = very high
EXAM - KNOW THIS
- r =0 means ___ relationship
- r = -1 means ___ relationship
- r = +1 means ___ relationship
no relationship
inverse relationship
positive relationship
