PRIDI 2013 Design

Quantitative Study
  • Overall approach to data collection
    • Proctored assessment and interviews
Target population
  • Children ages 2 to 4
  • Two sub-groups:
    • Children 24 to 41 months of age
    • Children 42 to 59 months of age
Sample design
Three-step strategy


  • Primary Sampling Units (PSUs) – established according to geographic or administrative region
  • PSUs stratified as urban or rural on the basis of each country’s own definition



Secondary Sampling Units (SSUs) – households randomly selected within the PSUs



  • Only one child per household was allowed to participate in PRIDI.
  • If the household had more than one child ages 2 to 4, the participating child was determined via a Kish selection grid.
Sample size


  • At least 2,000 children per country
  • 1,000 children 24 to 41 months of age
  • 1,000 children 42 to 59 months of age



7,710 children in 4 countries

Data collection techniques and instruments

Child development test in domains mentioned above

  • Standardized test
  • One-on-one test situation
  • Administered and guided by a test administrator with rich amount of incentive material for the various test assignments
  • Two test forms: Form A administered to those under 42 months of age, Form B to those 42 months and older; the forms were very similar, but the overall difficulty of Form B was greater.


Contextual information about the household and the child

  • Face-to-face interview, usually with the mother or female guardian
  • Observations made by the interviewer with respect to the condition of the home
  • Measurement of height of child
  • individual interview
  • observation
  • development test
  • The study instruments were administered in three different languages.
  • The most common language: Spanish (all countries)
Translation procedures
  • Development of an international version of all assessment instruments in Spanish under supervision of the IDB
  • Translation into applicable languages of instruction by participating entities
  • Translation verification by linguistic and assessment experts in order to ensure equivalence with the international version
Quality control of operations

Measures during data collection

  • Participants were responsible for data collection within their own respective territories.
  • Standardized survey operation procedures: step-by-step documentation of all operational activities provided with manuals
  • Full-scale field test of all instruments and operational procedures (in each participating country and entity)
  • Provision of software tools for creating and checking data files
  • Training provided for national research coordinators (NRCs) and their staff, for test administrators, etc.


Measures during data processing and cleaning

  • Data processing at the IEA using Statistical Analysis
  • Software (SAS)
  • Testing of all data cleaning programs with simulated data sets.
  • Material Receipt Database
  • Standardized cleaning process
  • Repetition of data cleaning and comparison of new data sets with the preceding version
  • Finally, identification of irregularities in data patterns and correction