Guided Notes: Descriptive Statistics
Objectives:
Distinguish ____________________________________________________________.
Apply basic _____________________________, including interpreting and constructing ______
and calculating simple descriptive statistics (e.g.,____________________________________).
Statistics:
●​ Definition: The use of math to __________________, ________________ and
________________ numerical data from research.
●​ 2 Types of Statistics:
1.​ Descriptive: used to_____________________research data
2.​ ______________: used to _______________ data and ___________
conclusions from research data
Descriptive Statistics (Describe & Summarize):
1. Graphing Data:
●​ Frequency Distribution: An ___________________ indicating the________ of each
score or group of scores.
○​ Used to ____________ research data
○​ Used to make _____________.
■​ Y-axis: _______________
■​ X-axis: ________________
2. Types of Psychological Data: (Discrete Data)
●​ Nominal:
○​ __________
○​ _______________________l; ___________ compute mean.
○​ Represented by_______ graphs (e.g., Favorite ice cream flavor).
●​ Ordinal:
○​ _____________
○​ _______________; ____________ compute mean.
○​ Represented by_______graphs (e.g., 1st place, 2nd place, 3rd place).
3. Types of Psychological Data: (Continuous Data)
●​ Interval:
○​ Equal _____________________; no true _______ point.
○​ Numerical; ________compute mean.
○​ Represented by _______________(e.g., Degrees in Fahrenheit).
●​ Ratio:
○​ _________________ between points;________________ point.
○​ __________________; can compute mean.
○​ Represented by__________________ (e.g., _______________).
4. Histogram: ________________________________ that presents data from a
___________________________
5. Frequency Polygon: __________________________________ that presents data from a
___________________________
6. Measures of Central Tendency:
●​ Median: _______________________________________of a distribution
●​ Mean:__________________________________of a distribution
●​ Mode: __________________________________ in a distribution.
○​ Bimodal: _________________________
7. Measures of Variation/Dispersion:
●​ Range: _____________________________________in a distribution.
●​ Standard Deviation: ___________________________________________
●​ Variance: ___________________________________________
8. Standard Score:
●​ Z-Score: The number of__________________________________ for a particular score.
○​ -z: Scores _______________the mean.
○​ +z: Scores ______________ the mean.
●​ Z= (X−M)/____
​
9. Types of Distributions:
●​ Normal: ________________, bell-shaped distribution.
○​ ***Mean, median, mode fall ________________ at the same point
●​ Positive Skewed Distribution: __________________________, skewed distribution
○​ ***Mode, median, mean (caused by an outlier with a HIGH score).
○​ ***Most scores are low; scores pile up at the low end of the scale.
●​ Negative Skewed Distribution: ______________________, skewed distribution
○​ ***Mean, median, mode (caused by an outlier with a LOW score).
○​ ***Most scores are high; scores pile up at the high end of the scale.
10. Percentile Score:
●​ Percentile:The _______________________ zero.
○​ Measures__________________ for comparable scores.
○​ Indicates ___________________________________ a given score.
○​ Each 25% is known as a ______________
11. Skewed Distributions:
●​ Caused by Outliers:
●​ Outliers: ____________ scores
○​ affect measures of________________
●​ Since the median splits your data __________, it will always fall between the
_____________________________, regardless of whether your distribution is
positively or negatively skewed
●​ The Mean___________________ to the outlier.
12. Negative Skewed Distribution:
●​ The order of the measures of central tendency are _________________________
●​ Caused by an _________ with a __________ score
●​ Most scores are ________________
●​ Scores pile up at the ______________ of the scale
13. Positive Skewed Distribution:
●​ The order of the measures of central tendency are _____________________
●​ Caused by an outlier with a _____________ score
●​ Most scores are___________
●​ Scores pile up at the_______________ of the scale