Malawian physical science teachers (PSTs) perceive nuclear physics to be the
most difficult physics topic. This study investigated: reasons PSTs would give for
this perception, teaching strategies that some PSTs would use to address learning
difficulties in nuclear physics, reasons the teachers would give for using certain
strategies and nature of the PSTs’ pedagogical content knowledge (PCK) in
nuclear physics. Assumptions of the interpretivist paradigm and the theoretical
framework of PCK guided the data collection, organisation and analysis
processes.
Thirty teachers completed a questionnaire, which enabled me to identify PSTs
who chose nuclear physics as the most difficult, difficult aspects of nuclear
physics and reasons those aspects are difficult. Stratified purposive sampling was
then used to choose four case teachers. I observed two lessons on nuclear physics
for each case teacher by video recording them. I interviewed each case teacher
before and after both lessons. I also interviewed a group of students after each
lesson. Video recordings were discussed with the respective teachers. Some
documents were collected. All interviews and video recordings were transcribed
into text, coded using Atlas.ti 5.2 and analysed inductively. Content analysis was
used with documents.
Some learning difficulties surface during lessons and they mainly related to
student conceptions, nature of concepts and mathematical manipulations. The case
teachers could not anticipate most of them, irrespective of qualification. It would
seem the teachers were hardly aware of lesson-specific difficulties.
The case teachers used combinations of strategies that focused on transmission of
information. The teachers hardly probed student thinking. Reasons given for
strategies adopted revealed that qualified teachers emphasised only content while the under-qualified ones also emphasised pedagogy. iv
Also qualified case teachers ascertained student understanding more frequently
than the less qualified ones. Also one of the qualified teachers was able to
articulate main ideas of the lessons, while the other three could hardly do so.
I conclude that teachers with similar characteristics as those studied here need
assistance to develop the following aspects of PCK in nuclear physics: awareness
of learning difficulties, use of strategies that are based on student thinking and ability to articulate main ideas