A diagnostic probe
This is one of a set of classroom resources designed to assist teachers in diagnosing student thinking, including common alternative conceptions ('misconceptions'). These resources are published by the Royal Society of Chemistry (RSC), and are available for free download.
The resources are intended for diagnostic assessment, and although teachers can set them as exercises to be collected in, the probe may be more productively employed as the basis of pair/small group work followed by a teacher-led classroom discussion. (The purpose is not to grade or score learners' current understanding, but to identify misunderstandings and unhelpful intuitions in order to shift thinking towards the scientific accounts and models.)
Read about diagnostic assessment
This resource consists of three parts:
There are some questions asking student asking students about what is going on at the submicroscopic level in a precipitation reaction.
If students answers those question well, then the other materials may not be needed.
For students who lack or have confused/incorrect ideas about the mechanism, there is a structured worksheet leading them through the process.
A second set of question ask about a different precipitation reaction. This might be useful as a kind of post-test if students have been assigned the structured questions as a remedial exercise, having initially performed poorly on the first set of questions.
For each probe, the RSC provides the instrument which can be copied for classroom use, plus documentation to guide the teacher in using the probe.
The materials are copyright, but may be freely used in educational contexts. (For permission to use for any other purpose, please contact the RSC).
The resources are available either in book form or as free downloads.
The book
The book version is:
Taber, K. S. (2002). Chemical Misconceptions – Prevention, Diagnosis and Cure: Classroom resources (Vol. 2). London: Royal Society of Chemistry.
The book derives from a Royal Society of Chemistry Teacher Fellowship project that developed materials to support diagnostic assessment in the science / chemistry classroom
The book is available for sale from the Royal Society of Chemistry or other booksellers.
This accompanies Chemical Misconceptions – Prevention, Diagnosis and Cure, Volume 1: Theoretical background
Free downloads:
The probes can also be downloaded from the RSC website:
