A cross the world, Assessment for Learning (AfL), or formative assessment, is recognised as a central component of effective teaching and learning. However, tools to measure the extent to which teachers use AfL practices in classrooms, or to evaluate the extent to which programmes of by educational researchers to measure change in classroom practices before and after professional development in AfL. THE ASSESSMENT FOR LEARNING MEASUREMENT INSTRUMENT (AfLMi) The AfLMi is based on an earlier instrument created by the researchers called the Assessment for Learning Audit Instrument (AfLAi). Developed using data from 594 teachers from 44 elementary schools in Ireland, the AfLAi consists of 58 statements describing different classroom practices across four key AfL strategies: sharing learning intentions/success criteria (LISC), questioning/classroom discussion (QCA), feedback (FB), and peer/ self-assessment (PSA) (see Lysaght & O’Leary, 2017). An instrument for measuring Assessment for Learning (AfL) in the classroom This article introduces educational researchers to the Assessment for Learning Measurement instrument (AfLMi). Based on research by Zita Lysaght and Michael O’Leary at Dublin City University, in partnership with Larry Ludlow at Boston College, the AfLMi consists of 20 statements relating to four key assessment for learning (AfL) strategies recommended in the assessment literature. As designed, the instrument is intended for use in intervention studies designed to measure the extent to which AfL is embedded in classroom practice prior to, during, and following professional development in AfL. The AfLAi is used internationally by teachers and schools to self-evaluate the degree to which AfL practices are embedded in their classrooms based on a fve-point scale: 5. Embedded = happens about 90% of the time; 4. Established = happens about 75% of the time; 3. Emerging = happens about 50% of the time; 2. Sporadic = happens about 25% of the time; 1. This Never happens However, while the AfLAi provides comprehensive data, not all 58 statements are needed for measurement purposes in research contexts. Hence, the team developed a more streamlined instrument that captures the key elements of AfL classroom practices in a manner that meets the validity and reliability requirements of a high-quality measurement tool. DEVISING THE SHORT- FORM INSTRUMENT In devising the shorter-form instrument (AFLMi), the researchers applied a Rasch model to data derived from the original administration of the AfLAi (58 statements) to determine item diffculties. Based on the outcomes of this analysis, and qualitative judgements to ensure content validity, 20 statements from across the four AfL strategies were selected for use in the AfLMi. These are shown in Table 1. The 20 statements, identifed by their acronyms and numbers, are also included in the variable map that was derived from the Rasch analysis (Figure 1). THE AfLMi VARIABLE MAP The variable map in Figure 1 features two grouped distributions: one for the 20 statements (arranged to the right of the map’s central vertical line) and one on the left for the 594 teachers in the study (each # = 4 teachers). At the bottom of the AfLMi measurement scale are those items that are easy to ‘embed’; in other words, those practices which teachers are likely to employ in their classrooms as a matter of routine. An example might be: Child-friendly language is used to share learning intentions with pupils (LISC3). As we climb up to the top of the scale, we fnd those classroom practices which are least likely to be embedded in a teacher’s arsenal, for example: Pupils are encouraged to record their progress using, for example, learning logs (PSA2). The researchers found that this arrangement was generally consistent both with extant theory as well as their own classroom observations (made predominantly in the Irish context). The map also shows high-scoring (highly skilled) teachers in the top-left (ie, those with the most practices embedded in their usual classroom activities), while those less-skilled teachers appear in the lower-left corner of the map. Beside the variable map in the fgure are details with respect to raw scores and logit scores (measure). It will be recalled from earlier in this article that a score of 5 on the AfLMi corresponds to a practice that is embedded, a desirable response that indicates an AfL practice that is being implemented frequently in a classroom. A score of 1, on the other hand, corresponds to a Never response, an undesirable outcome. Hence, the maximum raw score possible is 100 (ie, 20 x 5), while the minimum is 20 (ie, 20 x 1). A teacher’s total score can be obtained by summing The AfLMi can be used for research purposes when tracking the ongoing adoption of AfL practices in the classroom. Zita Lysaght, Michael O’Leary & Larry Ludlow Education & Training︱ professional development in AfL are successful in bringing about change, are in short supply. Researchers at Dublin City University and Boston College set out to fll these gaps. This article is focused specifcally on the Assessment for Learning Measurement instrument, or AfLMi. The instrument can be used Monkey Business Images/Shutterstock.com www.researchoutreach.org www.researchoutreach.org