Faculty of mathematics and physics University of Ljubljana

Spicy physics

Aleš Mohorič, Sergej Faletič

Faculty of mathematics and physicsUniversity of Ljubljana

Recipe to improve physics teaching:

• knowledge.........a lot• enthusiasm........planty• ICT.....................teaspoon (as a spice)

Examples of ICT use: • personal respond system (PRS or “clickers”)• electronic sensors with computer interface• e-learning portal www.nauk.si

PERSONAL RESPONSE SYSTEM

“CLICKERS”

Familiar?

me, me...

her, her...

Solution?

Brief, multiple-choice questions

Immediate analysis by electronic responders

Basic rules in clicker use

• explain the procedure• explain the handling with clickers• emphasize the anonymity of responses• activity begins with an experimental question• read the question aloud before seting up the timer• the display shows a histogram of responses

• test existing knowledge• verify the effectiveness of homework• test recall of lecture point• choose the next step in a complex calculation• reveal pre-existing perception• check conceptual understanding • use of the concepts in a new context• predict the results of the experiments, simulations, video, etc..• compare various representations (graphical,

mathematical, ...)

Purpose of questions

Procedure

• question • vote• peer discussion• vote • whole-class discussion

Basic rules in clicker use

• do not reveal the correct answer• if the majority of students chose the correct answer,

volunteer explains the correct answer and why other are wrong

• for uneven distribution of responses, the students discuss the question in pairs, after a few minutes, repeat vote

• representatives of specific groups (in terms of representation of responses) explain why they chose the selected answer (it is better if we start with the group who chose the wrong answer)

Basic rules in clicker use

• at the end tell which answer is correct• why is it correct (explanation)• why the other answers are incorrect• summarize the explanations of students• thus recognizing students and encourage them to

continue to participate in the discussion • teachers should be sensitive and open to any

criticism that students give to each question

Poor use of clickers• solely for taking attendance• for quizzes or high-stakes testing• only occasionally, or at set times

Better use of clickers• integrated into lecture, frequent• require or encourage peer instruction• mix of difficulty• generous credit for any answer• low grade impact (~2%)

Poor Concept Tests• merely test recall• involve blind application of formula/recipe• involve many numbers

Better Concept Tests• check qualitative understanding (no calculator)• apply familiar skills in new contexts• multiple questions to lead thru multi-step reasoning• test a learning goal

Calculate the current in 2 ohm resistor and potential difference between P and Q

When S is closed, what happens to:(a) intensities of A and B?(b) intensity of C?(c) current through battery?(d) potential difference acrossA, B, and C?(e) the total power dissipated?

Some considerations

• too easy questions seen as a quiz (entertainment)

• may mislead students for the test

• challenging questions are most useful for learning

• order is important: start easy, hard in the middle, end easy

• 4-6 options for answer (min 3)

• the easiest way: google “ConcepTests” (http://galileo.harvard.edu/http://www.mines.edu/Academic/physics/classroomcommunicators/assets/banks.html.)

Technicalities

• infrared (IR) clickers infrared (IR) clickers are cheaper than the radio are cheaper than the radio frequency (RF)frequency (RF) clickersclickers

• IRIR perform performance (ance (reception of responsesreception of responses, , longer longer minimum time between two receptionminimum time between two receptions, ranges, range, , handles onlyhandles only up to 30 up to 30 clickers clickers)) worse than RF worse than RF

• clickers with alclickers with alpha-numeric characters, pha-numeric characters, (not (not widespread)widespread)

• PRS is independent of presentationPRS is independent of presentation• up to the user to map presentation to PRSup to the user to map presentation to PRS

Examples

What is your age?

1) 10-20 yrs

2) 20-30yrs

3) 30-40 yrs

4) 40-50 yrs

5) 50-60 yrs

6) > 60 yrs

I have taken or taught a class that used clickers.

TRUE

FALSE

Examples

A box of mass m is held stationary against a vertical wall. There is friction between the wall and the box. The direction of the force of friction exerted on the box by the wall is...

(A) up

(B) down

(C) zero

(D) not enough information given to answer the question.

Examples

A toy car with mass m moves along a massless wooden plank lying horizontally over two support posts, as shown. The car is rolling across the bridge from point P2 to point P3,(left to right). What can you say about the magnitude of the net torque (i.e. the sum of all torques) about the point P1?(A) It is increasing.(B) It is constant, and zero.(C) It is decreasing.(D) It is constant, and non-zero.(E) Not enough information is given.

ACTIVITY:Write a clicker question

• pick a concept or skill you think is important and/or difficult for students.

• identify any common misconceptions to use as distractors.

• write the question as simply and clearly as possible.

ACTIVITY:Respond to histograms

A wrongB correct A correct

ELECTRONIC SENSORSAND

COMPUTER INTERFACE

Vernier LabPro interface

data-collection system- 4 analog channels, over 50 different sensors, (temperature, dissolved oxygen, gas pressure, pH, force...)- 2 digital channels (motion detectors, photogates, radiation monitors, rotary motion sensors, and drop counters)

Accelerometers Barometer

Blood Pressure Sensor

Charge Sensor

CO2 Gas Sensor

Colorimeter

Conductivity Probe

Current Probe

High Current Sensor NEW

Differential Voltage Probe

Digital Control Unit

Dissolved Oxygen Probe

Drop Counter

Dual-Range Force Sensor

EKG Sensor

Electrode Amplifier

Flow Rate Sensor

Force Plate

Gas Pressure Sensor

Vernier GPS Sensor NEW

Garmin® GPS Units

Gas Chromatograph NEW

Hand Dynamometer

Hand-Grip Heart Rate Monitor

Instrumentation Amplifier

Ion-Selective Electrodes Light Sensor

Magnetic Field Sensor

Microphone

Motion Detectors O2 Gas Sensor

Ohaus Balances

ORP Sensor

pH Sensors

Photogate

Power Amplifier NEW

Digital Radiation Monitor

Relative Humidity Sensor

Respiration Monitor Belt

Rotary Motion Sensor

Salinity Sensor

Sound Level Meter

Soil Moisture Sensor

Spectrometers

Spirometer

Temperature Probes Thermocouple

Turbidity Sensor

UV Sensors

Voltage Probe

Watts Up Pro NEW

Wireless Dynamics Sensor System

Technicalities

• Lab Pro interface, USB• Logger Pro software• one licence per school• sensors sold separately

Innovative uses

• high CO2 levels putting you to sleep?• investigating periodic trends• spectral analysis of fireflies• how do you dim an LED?• showing speed and location in Google maps• test hearing response with labquest• studying the diving reflex in the laboratory

http://www.vernier.com/innovate/index.html

ACTIVITY

motion detection / graphical representation

plot a graph x(t) or v(t) and try to repeat it!

E-LEARNING PORTALNAUK

www.nauk.si

e-learning portal www.nauk.si

GOALS:

• active students• didactical recommendations• feedback• fresh, everyday cases• include measurements

Advantages

• adjust the level based on responses• union of peer-instruction and self-learning• simulation and playing based learning

• disengaging the reality• overuse of ICT saturates students• e-learning is effective only for intro courses

Disadvantages

Types of material

• multiple choice questions• context rich exercises

Multiple choice questions• graphic material, • real context, • multilevel responses – hints/solutins• adjustable number of repetitions• record of succes rate• variation of answers• different answer modes

Context rich exercises

wrong

wrong

correct

...end

• central story with special cases • modular composition• graphic material• real context, • multilevel responses – hints/solutins• “exploring the landscape”• analysis of measurements

Tools

• reading the graphs• measuring distances, angles• ploting lines, vectors, curves• sky map• linking...

Example

Odboj teniške in žonglerske žogicehttp://www.nauk.si/materials/258/out/index.html#state=1

e-nauk

ACTIVITY

• open source• do it yourself• wiki type syntax...

• write a multiple choice question• write a scenario for a context rich exercise