Thumbnail Image

Introduction to Item Response Theory Applied to Food Security Measurement

Basic Concepts, Parameters and Statistics

Year of publication 2014

Pages 18 p.

Author Nord, Mark;Statistics Division

Product type Project

Edition 1

Synopsis (short abstract) The single-parameter logistic item response theory (IRT) measurement model (commonly known as the Rasch model) provides a theoretical base and a set of statistical tools to assess the suitability of a set of survey items for scale construction, create a scale from the items, and compare performance of a scale in various populations and survey contexts. It has been used widely as the statistical basis for survey-based experiential food security measurement. An important step in the validation of food security data is to assess the extent to which the data are consistent with assumptions of the measurement model. In data that meet those assumptions, household raw score (the number of items affirmed by the household) is an ordinal measure of the severity of food insecurity in the household, and the household severity parameter is an interval-level measure of severity. Neither of these important measurement traits is certain if model assumptions are not met. The psychometric validation pro cess is important in initial surveys of language groups and culturally distinct subpopulations and in previously untested modes of survey administration (such as self-administration or on-line administration). Once a set of questions has been assessed in a large sample of a population or subpopulation and found to adequately meet assumptions of the measurement model, psychometric assessment in subsequent surveys may not be necessary. However, psychometric assessment can be valuable in surveys wi th important policy implications to increase confidence in the findings. This paper presents basic concepts and mathematics underlying the Rasch model and describes the model parameters and statistics commonly used to assess food security survey data.

Language English

Also available in:
No results found.

Related items

Showing items related by metadata.

  • Thumbnail Image
    Meeting
    The Coping Strategies Index: A tool for rapidly measuring food security and the impact of food aid programs in emergencies
    FAO International Workshop on “Food Security in Complex Emergencies: building policy frameworks to address longer-term programming challenges” Tivoli, 23-25 September 2003
    2003
    Also available in:
    No results found.
    This paper looks at the Coping Strategies Index, which was developed by CARE to provide regular measurements for monitoring changes in food security and assessing the impact of food aid interventions in highly food insecure countries. The CSI is an indicator of household food security that is relatively simple and quick to use, straightfoward to understand and correlates well with more complex measures of food security.
  • Thumbnail Image
    Brochure, flyer, fact-sheet
    Voices of the Hungry Food Insecurity Experience Scale: One Metric for the World
    Infographic
    2016
    Also available in:
    No results found.
    FAO launched the Voices of the Hungry project in 2013 to provide up-to-date information about food insecurity that is policy-relevant and contributes to strengthening political will - information that speaks to people and leads to change.
  • Thumbnail Image
    Book (series)
    Compendium of food consumption statistics from household surveys in developing countries
    Volume 2 : Africa,Latin America and Oceania
    1994
    Also available in:
    No results found.
    This first issue of the publication presents data not only from the recent surveys but also, in a number of cases, from some undertaken as far back as the 1970's in order to provide some perspective of the changes over time. However, because of the many surveys involved, it is divided into two volumes: Volume 1,1 covering the surveys conducted in the developing countries in Asia, and the present Volume 2, covering the surveys conducted in the developing countries of Africa, Latin America and Oceania. Another compendium covering the surveys conducted in developed countries will be issued, probably in 1995, following the computerization of all the available survey data in the FAO Statistics Division's database. Subsequently, a single compendium, updating the information, will be periodically issued.
Show more

Users also downloaded

Showing related downloaded files

No results found.