PSYC105 Lecture 4: PSYC105 STATISTICS Lecture 4: Summarising Data
18 May 2018
School
Department
Course
Professor
PSYC105 STATISTICS
Week Four: Summarising Data
Lecture Overview
- Presenting data
o Listing vs summarising
- Categorical data
o Frequency tables
o Bar charts and pie charts
- Numeric data
o Typicality
o Variability
o Shape
- Normal distribution
- Other graphs
Presenting data
- Once data has been collected, researchers need to think of how to present the data
- Data can be presented in two formats
o Listed (better for small amounts of data)
o Summarised
Summarising Data
- To communicate our findings, and prepare for data analysis, we need to summarise
data
- Two types of summary displays
o Numeric summary
o Graphical summary
- Appropriate summary depends on the kind of data
- Categorical data: discrete categories or groups
o Frequency tables and bar chart / pie chart
- Numeric data: a score on a scale
o Numeric summary statistics (mean/median/mode, standard deviation) and
histogram
- Think about
o Typicality: what is the most common or typical score/category?
o Variability: how much do the scores/categories vary or fluctuate?
o Shape: what is the shape or pattern of the distribution?
Typicality
- The most typical score
o Middle score
o Average score
o Most common score
- Three types of typicality
o Mean: arithmetic average
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Document Summary
Categorical data: frequency tables, bar charts and pie charts. Once data has been collected, researchers need to think of how to present the data. Data can be presented in two formats: listed (better for small amounts of data, summarised. To communicate our findings, and prepare for data analysis, we need to summarise data. Two types of summary displays: numeric summary, graphical summary. Appropriate summary depends on the kind of data. Categorical data: discrete categories or groups: frequency tables and bar chart / pie chart. Numeric data: a score on a scale: numeric summary statistics (mean/median/mode, standard deviation) and histogram. The most typical score: middle score, average score, most common score. Three types of typicality: mean: arithmetic average, median: middle-most score (ranked from lowest to highest, mode: most common score. How spread out or varying or dispersed the scores are. Scores could be tightly clustered together, or very spread out. Qua(cid:374)titative (cid:894)(cid:374)u(cid:373)eri(cid:272)(cid:895) varia(cid:271)les are ofte(cid:374) (cid:858)(cid:374)or(cid:373)ally distri(cid:271)uted(cid:859)
