There is growing interest in observing teacher's classroom practice, for formative feedback to teachers, teacher performance evaluation and incentives, programme impact evaluation, and research on the determinants of student learning.  For observations to generate meaningful data, they must be carried out using valid instruments, standardised protocols, and trained observers.  A number of different observation instruments have been used in the US, but only two have gained any traction to date in developing countries – the Classroom Assessment Scoring System (CLASS) and the Stallings classroom observation instrument.  Although both have been validated in developing countries in connection with student learning outcomes, they have never been used in the same setting. 

This paper exploits an ongoing research programme that used the CLASS instrument to assess 7th grade mathematics classrooms in Chile. In this research we re-code the same teacher videos using the Stallings instrument.  We generate the first global evidence on the comparability and validity of the dimensions of teacher practice they measure.  Because CLASS is significantly more expensive and complex to use – its training materials are proprietary and observers require a high degree of skill – there is a policy and research interest in analysing the degree to which the simpler, open-source, Stallings instrument produces similar results. 

We ranked the Chilean teachers on their scores in each of the CLASS instrument’s three domains (classroom organisation; emotional support and instructional support) and analysed the resulting quartile distributions’ correlations with key Stallings measures of teacher performance.  We found that teachers’ scores on the classroom organisation domain of CLASS were modestly correlated with the most important Stallings measures, in all cases in the directions expected and with statistical significance. Teachers’ CLASS scores on classroom organisation were positively correlated with their use of time for instruction (r=0.340, p=0.015) and negatively correlated with time spent on classroom management (r=-0.321, p=0.022).  Teachers in the bottom quartile of the distribution averaged only 80% of time on instruction, while those in the top quartile averaged 90%. Time on classroom management in the top quartile was a very low 9% of class time, while the lowest quartile spent 17%.  All differences were statistically significant at the 5% or 1% level. 

Teachers’ scores on the CLASS classroom organisation domain were also positively correlated with the Stallings measures of teachers’ ability to keep students engaged.  However, Stallings measures were not correlated with teachers’ scores on the other two CLASS domains: instructional support and emotional support.  In fact, we found a statistically significant negative correlation between teachers’ scores on the emotional support domain of CLASS and teachers’ ability to keep students engaged academically, a result that merits further research. 

Use of the CLASS and Stallings instruments in developing countries is in its infancy.  Our study provides some early evidence that in their area of overlap, these two instruments produce consistent assessments of teachers’ effectiveness in managing their classrooms and that these skills are important for student learning.  This suggests that both instruments have potential to help teachers improve their practice and help school systems raise student learning.  The main strength of the Stallings instrument is its suitability for larger-scale studies in representative samples of schools, to benchmark efficiency-related dimensions of education system performance or to evaluate the impact of new education programmes or policy reforms on system efficiency.  From the sample of teachers observed, Chile may be ready to tackle the more complex teaching skills because efficient classroom management is largely achieved. The observed teachers could benefit from CLASS-type feedback. But teachers in many other developing countries still struggle with time and behaviour management. For them, Stallings can be very useful, perhaps more than CLASS at this stage, and at much lower cost.