Units of Analysis and data structure - PowerPoint PPT Presentation

Loading...

PPT – Units of Analysis and data structure PowerPoint presentation | free to download - id: 7aff6f-MGZkN



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Units of Analysis and data structure

Description:

Units of Analysis and data structure The Basics * We are going to spend some time today reviewing the importance of the unit of analysis in the statistical and data ... – PowerPoint PPT presentation

Number of Views:133
Avg rating:3.0/5.0
Slides: 32
Provided by: Chuck188
Learn more at: http://3stages.org
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Units of Analysis and data structure


1
Units of Analysis and data structure
  • The Basics

2
Outline
  • Definitions
  • Elements of the unit of analysis
  • Data structure

3
Unit of observation
  • The unit of observation is a basic concept in
    quantitative research that represents the objects
    that are observed and about which information is
    systematically collected.

4
Unit of analysis
  • The unit of analysis is the object about which
    generalizations are made based on an analysis.

5
Determination
  • The unit of observation is determined by the
    method by which observations have been selected
  • The unit of analysis is determined by an interest
    in exploring or explaining a specific phenomenon.

6
When they are the same
  • The unit of observation and unit of analysis are
    the same when the generalizations being made from
    a statistical analysis are attributed to the unit
    of observation.

7
Identifying units of analysis
  • The unit of analysis is shaped by three
    properties
  • Social entities
  • Time
  • Space

8
Social entities
  • observations of a single social entity, such as a
    person or an institution
  • observations of multiple entities with a defined
    relationship, such as family, employer-employee

9
Social Phenomena
  • transactional observations that are the result of
    actions among entities, such as labour strikes or
    international conflicts, including wars.

10
Time
  • observations made at one point in time a
    cross-sectional study

11
Time
  • observations made at multiple points in time
  • the data may be organized by time commonly
    referred to as a time series
  • time may structure some form of repeated measures
    of content or subjects

12
Space
  • observations made within a specific spatial area
  • observations made within a hierarchy of spatial
    areas

13
Substituting units
  • There may be requests for which data for a
    desired unit of analysis cant be delivered but
    for which data are available summarized over one
    of the other attributes of the unit of analysis.

14
Substituting units
  • Example
  • Request for firm-level data for NAICS 312
    Beverage and Tobacco Product Manufacturing
  • Ideal source microdata on establishments from
    the Canadian Census of Manufacturers
  • No access to enterprise microdata

15
Substituting units
  • Example NAICS 312
  • Alternatives are there aggregate data
    summarizing the firms within NAICS 312?
  • Possibilities summaries over time (time series)
    or geography (small-area business statistics)

16
Statistical data structure
  • Lets review basic data structure.
  • The unit of analysis defines the underlying
    structure of a data file.

17
Statistical data structure
  • This structure consists of a series of rows with
    each row containing the data of one member of the
    unit of analysis.
  • This simple structure is known as the flat,
    rectangular data matrix.

18
Statistical data structure
Case n-1
19
Statistical data structure
  • All of the information collected for each member
    of the unit of analysis is organized in a fixed
    location in the file called fields or variables.

20
Statistical data structure
Case n-1
21
Statistical data structure
22
Statistical data structure
  • This structure looks like the grid of a
    spreadsheet. However, there is one very
    important difference between a statistical data
    structure and a spreadsheet.
  • The spread sheet is organized around individual
    cells, while the statistical data structure is
    organized around the rows.

23
Statistical data structure
Spreadsheet
24
Statistical data structure
Spreadsheet
Cell B2
Cell E3
Cell C5
Cell F7
25
Statistical data structure
Statistical Data Structure
Row 1
Row 3
Row k-1
26
Statistical data structure
  • The next slide presents the way that this simple
    statistical data structure appears in SPSS.

27
(No Transcript)
28
Row 1
29
Row 8
30
Row 8
Row 15
31
Field 8
Row 8
Row 15
About PowerShow.com