This is post 2 on laboratory practicals, sparked by discussion on Twitter of A-level science reforms to replace practical assessment with an endorsement. In post 1, I considered that the only way to assess practical work directly is to observe students doing practical work. In this post I’m aiming to consider the impact that prior experience of practical work has on 1st year chemistry students.
We overtly assume little when it comes to the practical skills of our incoming students. Take an group of students and they will have sufficiently diverse backgrounds that make assumptions very dangerous. Our lab course is designed to build up the basic skills in the first semester. That’s not to say we go slow, and that’s not to say that good prior experience doesn’t help, but we go at a reasonable pace and knowing your way around a lab is an advantage. We do, however, unconsciously assume a great deal about the practical skills of our incoming students, but this is practical skills in a far broader context.
Firstly, we assume that students can follow instructions to carry out practical procedures and that it goes without saying that this involves gathering equipment, planning an efficient way to do work, working in an organised and tidy manner, and cleaning up effectively. I think this is a fair assumption to a point. These skills rely on extensive experience of lessons in all subjects that aren’t just sitting doing worksheets. That can be anything from art to home economics, chemistry to woodwork. It can be hobbies or clubs, activities with family, friends, scouts or guides. And yet it seems that some students struggle with this kind of thing. Being aware of the surroundings and the other people working near by is essential here as well. Not leaving drawers or cupboard doors open, moving the stool so no one trips over it, returning items promptly after use. We assume that our students are used to working in a busy environment, again something that comes from experience.
Secondly, we assume that students are practiced at critiquing practical procedures and knowing when something isn’t right. I’m not talking about the mythical powers of any demonstrator to identify a product waved in their face and answer the ‘does this look right?’ question. I’m talking about the ability to use an ice bath so that the flask doesn’t tip, or recognise whether something is boiling or not. There are sometimes logic gaps in how people work in a lab that come down to a lack of experience of doing stuff.
Essentially, how can we hope to teach students to transfer air sensitive materials via syringe (even after 2 semesters of lab) if they are unaccustomed to translating written instructions into physical actions, incorporating verbal suggestions, finding equipment and performing basic tasks? Less practical work in any context is bad news for the first year lab class.