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Self-assessment: strategies and software to stimulate learning. Self-assessment with Certainty-Based Marking ( CBM ) Tony Gardner- Medwin Physiology ( NPP ), UCL www.ucl.ac.uk /~ ucgbarg. OU Workshop : 11th June 2012. knowledge uncertainty don't know misconception delusion.
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Self-assessment: strategies and software to stimulate learning Self-assessment with Certainty-Based Marking (CBM)Tony Gardner-MedwinPhysiology (NPP), UCLwww.ucl.ac.uk/~ucgbarg OU Workshop : 11th June 2012
knowledge • uncertainty • don't know • misconception • delusion Decreasing certainty about what is true. Increasing certainty about something false. Increasing "ignorance" Knowledge crucially depends on certainty • A lucky guess is not knowledge • A firm misconception is far worse than acknowledged ignorance • So why do we usually mark students as if these things weren’t true? Knowledge = justified true belief ? ?
Certainty-Based Marking (CBM) <67 % mid >80% • CBM rewards thinking: • identification of uncertainties • or of justifications • Highlights misconceptions • negative marks hurt! • Engages students more • Enhances reliability & validity
Theoretical basis of CBM scoring (T/F Qs) Ignorance (nescience) = -log( P assigned to the correct answer) (Kullback-Leibler divergence)
Multiple Choice (SBA) Qs NB Single-best-answer Qs can fail to identify even very substantial ignorance
Mathematics – where I started using self-tests • Maths / numeracy for 1st year medics • Very mixed abilities • Many don’t expect to benefit from formal maths instruction • Doctors must know what they can / can’t do reliably • CBM approach with unlimited self-test attempts: • Doesn’t offend able students • Allows students to find and extend areas of competence • Motivates learning without humiliation or incentives to cheat
What everyone needs to know about mathematics Danger – I fall into traps. Must always seek help! Stuff I just don’t understand ! Fine – I know what I’m doing here ! OK – but check carefully ! Adapted from: Drive time isochrones around airports in northern Finland. Creative Commons: http://en.wikipedia.org/wiki/File:Drive_time_isochrones_airports_northern_Finland.png
Pattern of initial and eventual success – med maths www.ucl.ac.uk/lapt?medmath No. of students (total 303) No. of repeated attempts at each of 3 maths exercises
LAPT – features built specifically for Self-Assessment London Agreed Protocol for Teaching (and Testing Of Physiology) • Certainty-Based Marking • Instant Feedback for each Q (local software, not server interaction) • Students opt whether or not to answer individual Qs & Sections • Marking normally expressed relative to just those Qs selected • Scores shown with & without CBM to assess reliability judgement • Breakdown showing % correct at each certainty level (C=1,2,3) • Students can make & see comments in context & wiki-edit quizzes • Entire quizzes editable as a single text file for staff convenience • Specific tools for maths & medicine (syntax checks, units, EMQs)
Good practice for good self-tests – My own views! Write a stimulating / didactic sequence of Qs mix easy & difficult Qs : for engagement, reward, realism include classic misconceptions – students learn through mistakes make chains of Qs : lead through the logic of a topic Explanations should widen the immediate issue to other contexts prompt the bringing together of different kinds of knowledge Clear navigation – students should be choosing what to do Allow use of study materials – tests shouldn’t be time-limited Encourage anonymous comments & dialogue Encourage working in twos or threes Don’t bother with adaptive tests (conditional jumps to specific Qs) the students should decide & choose what they need Never comment on a student’s mark in a self-assessment !
www.ucl.ac.uk/lapt www.tmedwin.net/cbm/moodle