The question
“A cart slides past at constant speed. How long is it at exactly x = 2.0 m?”
The correct answer is zero. In the point-particle model used here, the cart passes x = 2.0 m at one instant, and an instant has zero duration.
For physics teachers and department leads
Physics misconception diagnostics, marked and analysed for you.
Pick a topic for one class. We prepare the link, analyse the responses, and send back a class heatmap, a short report and matched teaching materials within 48 hours of completion. Students take part without creating accounts. The classroom pilot is free, with no commitment to continue.
IB DP · AP · A-Level · GCSE / IGCSE
The wrong ideas come from physics education research, which has recorded them since the 1970s: Viennot, Trowbridge & McDermott, Arons, Hestenes, Maloney. The physics comes from Arons, Knight, Moore, and Chabay & Sherwood.
11
Diagnostics Live
48h
Report Turnaround
No
Student Logins Required
10 · 9 · 3
Schools · Countries · Continents
18
Completed Runs
Pilot evidence
A finding from four pilot classes
Across four pilot classes at four schools, involving 54 IB DP and IGCSE students between May and July 2026, roughly seven in ten answered the instant-versus-interval question incorrectly. The classes averaged 77% to 89% on the diagnostic overall. These figures describe those four classes, not every completed pilot or a benchmark for other schools.
Schools are anonymised. Only aggregate results are shown. No student names or individual response records are included.
From a pilot
“I carried out a pilot test of the Physics Misconceptions Diagnostics with my Grade 11 (lower 6th) International Baccalaureate classes, as part of their revision for end of year exams. The tests covered Motion Foundations, Forces and Free-Body Diagrams - topics that are fundamental to the IB course as well as A’ level courses.
The tests were all set up by FundaFirst - all I had to do was point the students to web links. The students found the questions easy to access and to carry out. The information that came back from FundaFirst was incredibly useful, identifying areas where the class and/or individuals were weaker. These areas would have been much harder to identify without the tests. FundaFirst then provided concrete examples of how to address the misconceptions, with work sheets targeting these areas.
I will not hesitate to use FundaFirst’s diagnostic testing with future cohorts!”
Dr Tim Short, Physics Teacher, ACS International School Egham
Deliverables
Illustrative reports using synthetic data. These are not pilot results. Your own reports are built from your students’ answers.
One package, 48 hours after your class finishes. There is no charge and no obligation.
01
Class misconception heatmap
Every question, overall and by performance band, with the misconception labelled. You can compare answers across the class and see which questions your higher-scoring students also miss.
02
Cohort summary
The spread across bands, the most common misconceptions, the biggest gaps, and the students to watch. The prescription is a two-minute read, with the detailed analysis on the page after it.
03
Mistake museum
Each trap your class fell into, in plain language. What it is, why students hold on to it, and what the correct idea looks like.
04
Words that hurt
Common teaching phrases that feed the misconception, and the wording to use instead. Share it with the department.
05
Targeted worksheets, with solutions
Practice matched to the wrong ideas your class's answers point to. These are not general revision sheets.
Diagnostics
Eleven diagnostics, one method.
Run one, or run several. Each stands on its own and runs alongside your own assessment. Students use a shared link, with no accounts and no installs.
DiagnosticTopicFormsQuestionsMinutesBands
MotionFree classroom pilots · no student logins · shared link
Examples
Two questions and the ideas they probe
Kinematics · Trowbridge & McDermott 1980
“Two balls on parallel tracks, side by side at one instant. Same speed?”
The wrong answer reads position at one instant as speed.
The diagnostic records how often the class’s answers show that reading, and how it varies across performance bands.
Newton’s laws · the ghost force
“You throw a ball upward. At the very top, what forces act on it?”
The wrong answer adds an upward “force of the throw”. Only gravity acts at the top.
The diagnostic records how often the class’s answers expect a force in the direction of motion.
Method
We start from the wrong answers and work back to the right idea.
The report shows which misconception patterns the answers carry, how often, how they vary by performance band, and what to address next.
01
Diagnose
Responses are mapped to known misconceptions. The report shows misconception patterns in the class’s answers, alongside performance bands.
02
Confront
The worksheets ask students to compare a prediction from the wrong idea with a contrasting situation, and to reconsider the idea it rests on.
03
Reconstruct
Then come definitions built from how each quantity is measured, and worksheets designed to rebuild the idea from first principles rather than from a remembered formula.
Grounded in
AronsKnightMooreChabay & Sherwood
FCI · Hestenes, Wells & Swackhamer 1992TUG-K · Beichner 1994Trowbridge & McDermott 1980Viennot 1979CSEM · Maloney et al. 2001ZuzaGalili
Coverage
Each diagnostic builds on the one before it, and each can be run on its own. They cover IB, AP, A-Level and GCSE.
One sequence, from motion to electricity.
LiveMotion & kinematics
LiveLaws of motion
LiveMomentum
LiveEnergy
LiveProjectile & circular motion
LiveOscillations, waves & sound
LiveStatic electricity
LiveElectric fields
LiveElectric potential
LiveCurrent electricity
LiveMotion in electromagnetic fields
UpcomingMagnetism
UpcomingThermal physics
UpcomingQuantum & nuclear physics
Also from FundaFirst
The Lab
Classroom activities for the misconceptions the diagnostic found
A diagnostic shows which wrong ideas your class's answers point to. The Lab gives you classroom activities that run in a browser, built on the same misconception bands. They are free for teachers.
Open the Lab
Field guide
The Mistake Museum
89 entries across six mechanics topics. Each entry is one misconception, the wording to drop, and the wording to use instead. 187 pages.
View the book
Public companion
FundaFirst
The public site, with long playable essays on the ideas behind the equations, plus Standpoint.
Visit FundaFirst
Guides
Guides and essays to read first
Eleven teacher’s guides and five essays for teachers. Free to read, with no sign-up.
Guides (PDF)
About
Where the wrong ideas come from
FundaFirst HS is a ConceptArc Education initiative. Its diagnostics show teachers the wrong ideas behind their students’ answers, across the class and by performance band, and return matched remediation within 48 hours. The misconceptions it maps come from published physics education research. That research has recorded them for nearly fifty years, from Viennot in 1979 to the CSEM in 2001. The sources are named above and in every guide.
Classroom pilots are free. The founding-department programme, for schools that want the full sequence and a standing arrangement, opens in January 2027.
Free pilot
Tell us what your class is studying. We handle the setup.
Students need no accounts. You share a link, and they enter the name or code your school sets. Writing a diagnostic like this yourself, with responses mapped to known misconceptions, would take weeks. You do none of that. Within 48 hours of completion you get the heatmap, the cohort summary and ready-to-use remediation.
No installs · no student logins · no charge
Reply within 24 hours
Pilot request received
Thank you. We’ll email you next steps within 24 hours.
Or email admin@fundafirsths.com