How will equating be carried out?

This will involve two key approaches:

• • Expert translations, back-translations and adjustment with iterations until professional opinion is satisfied. This will involve two translators from the relevant country initially, followed by a group decision about the new version. Then, an independent back-translation is carried out and again, the group convenes. Suggestions for adjustments are made to one translator and if any sections of dispute remain and back translation is requested, which is again considered by the group. The IEA Standard for Translations and Verifying Translations will be followed (Gregory and Martin, 2001, Technical Standards for IEA, page 51).

  • Statistical techniques - we will be looking to create equated scales with items that do not exhibit undue differential item functioning. Rasch measurement (see Linacre, J.M. (2002). Understanding Rasch measurement: Optimising rating scale category effectiveness. Journal of Applied Measurement, 3(1), 85-106) will be used to equate scales where that is possible. It will not be possible in all cases and where it is not, only within country analyses will be included in any reports.