Statistical literacy

1
Statistical literacy

• Laine G.M. Ruus
• Data Library Service, University of Toronto
• 2006/05/04

2
Statistical literacy

• refers broadly to two interrelated components,
  primarily (a) people's ability to interpret and
  critically evaluate statistical information,
  data-related arguments, or stochastic phenomena,
  which they may encounter in diverse contexts, and
  when relevant (b) their ability to discuss or
  communicate their reactions to such statistical
  information, such as their understanding of the
  meaning of the information, or their concerns
  regarding the acceptability of given
  conclusions.  These capabilities and behaviors
  sic do not stand on their own but are founded
  on several interrelated knowledge bases and
  dispositions...".
• Source Gal, Iddo. Adults Statistical Literacy 
  Meanings, Components, and Responsibilities
  International Statistical Review70( 1) 1-25,
  April 2002

3
(No Transcript)
4
Stories

• The Metro article of 2006/05/03 chose to tell one
  story a growing trend of private or
  semi-private worship, rather than conspicuous
  worship in a public place (church, etc)
• Refers to a source, a Statistics Canada study.
  Found article entitled Who's religious? listed in
  the Statistics Canada Daily of 2006/05/02

5
(No Transcript)
6
Source Study Whos religious? The Daily
Tuesday, May 2, 2006
7
The Daily article refers to an article
in Canadian Social Trends, May 2006
The Stats Can Daily article refers in turn to an
article in Canadian social trends
8
which contains statistical tables, as well as
charts which help visualize some of the
statistics in the tables, including
9
(No Transcript)
10
What the Metro article got wrong

• Focused on only one of the stories in the
  Statistics Canada Daily/Social trends articles
• The phrase growing trend came from a different
  story, one of declining religious affiliation and
  church attendance
• Misinterprets the information in the table
• There is only one time period, therefore cannot
  identify a trend from this table
• Implies that a majority prefer private to public
  religious observance, but from the article and
  table it appears to be only 27-37 of the 21 of
  the population who attend religious services
  infrequently/never

11
Frequency of public religious observance (eg
frequency attend church, etc)
Frequency of private religious observance
Producing a similar cross-tabulation using the
original microdata provides support for a
slightly different variation on the story.
12
Standing the table on its head gives a
different interpretation of the data
Frequency of private religious observance
Frequency of public religious observance (eg
frequency attend church, etc)
Public religious observance (eg frequency attend
church, etc)
13
Statistical literacy skills include

• Ability to follow the trail of breadcrumbs to
  find the Canadian social trends article and the
  tables/charts that accompany it
• To assess the reliability of Statistics Canada as
  a source of statistics on religion ie what if
  any might Statistics Canadas bias be vis-à-vis
  religion?
• To assess the validity of survey-based
  information versus anecdotal information (the
  Metro article) ie are there other data sources
  that would provide better information on the
  question? How good is Statistics Canada at taking
  surveys that represent the population?

14
Statistical literacy skills include (contd)

• Ability to interpret the information provided in
  the table, including ability to visualize it

Frequency of religious practices on ones own
showing attendance at religious
services/meetings ()
Attend public religious services
Frequency of relgious practices on ones own
15
Statistical literacy skills include (contd)

• Ability to assess the significance of the
  information that is not in the table how many
  cases were there in this survey? Does this table
  tell us what of the population go to church
  once a month or more?
• Ability to assess cross-tabulations and
  percentages as appropriate descriptive statistics
  for this type of data are there other
  descriptive statistics that would have added to
  the information in the table, eg cell counts as
  well as row percentages?

16
Statistical literacy skills include (contd)

• Understand the role of the tests of significance
  that have been used ie, what does 95
  confidence interval mean?
• Understanding what has to be done to examine the
  influence of a third variable (eg gender, age,
  education, or province) on religious attendance
  private religious practice

17
In summary

• Like information literacy, statistical literacy
  includes
• determining information needs
• information access skills
• critical evaluation of sources
• understanding of the information
• Unlike information literacy, statistical literacy
  includes
• some understanding of data collection,
  descriptive statistics, significance, inference,
  and causality
• active involvement in process of
  creation/transformation of descriptive statistics