Concerns about use of online simulations

Concerns expressed both in research literature and by teachers about using simulations for practical experiments. The page looks at these concerns and how we have addressed them in design of the simulations. We also look at how the simulations can bring benefits and overcome the disadvantages of on-line practicals. Finally we look at some concerns about the limits of validity of online simulation such as whether it's valid to simulate imaginary or dangerous reactions are also discussed. We begin by looking at how specific concerns and how they have been addressed in the design of the online simulations:

• It's not currently possible to replace real hands on experience and to mimic the dexterity required in practical work:
  

  We have not tried to produce a wholesale replacement of practical exercises. We believe that practical skills are best honed in a real laboratory and have not attempted to mimic activities such as measuring volume, pipetting or titration.

• Simulations do the work for the student, students press a button and get the results, that's not how experiments work.

  An early version of this work was designed so the student's decided in advance the time or concentration at which to take a reading and the simulation took the readings for them. On consideration, this approach was abandoned as not addressing the above concern. Although it did provide the students with a certain amount of choice, they were basically typing in a set of times, rather than following the experiment in real time, checking the clock and taking reading themselves. It was replaced with a system where the student decides as the experiment is running, when to take a reading. The fact that the experiments run in real time also means that when a reaction takes place slowly, the student actually experiences a longer wait, reinforcing this fact.
  One area we did not address, which could usefully be addressed in the future, is to allow the student's to plot their data by hand on a graph.

• Simulations often provide the perfect picture, whilst experimental procedures are usually subject to errors, the evaluation of which is important in the student's education;

  In these online practical experiments, the main source of error comes from errors in the readings taken by the student. The experiment starts when the student mixes the reagents, not when the student starts the clock, so errors in starting the clock or in noting colour changes in the solution or in taking accurate concentration readings will all contribute to realistically imperfect results. However, we recognise that there are other sources of error that could be included:

  • Random errors in accuracy of the concentration of the supplied reagents
  • Errors/drift in readings taken by simulated equipment
  If these sources of error are to be included in simulations, then the teacher and students should be made aware of their existence and the teacher should be able to control whether they are used and their magnitude.

• In real life it is possible to make mistakes. Simulated activities often provide users with a set of valid choices only.

  Learning can happen when students make mistakes or fail do accomplish a task if they are given feedback and an opportunity to reflect on what has happened. In these simulations there are opportunities for students to make mistakes, for instance they make define a number of experimental runs which do not provide a controlled experiment, if this happens, they will be warned about the validity of their results, but they can ignore the warnings and continue if they please. When it comes to examining the results, students can choose plotting options or define graph axes which are inappropriate for their needs. In this case, there is currently no explicit feedback (this could ultimately be provided if the simulation were linked with an assessment engine) and we would currently anticipate the teacher providing feedback where necessary.

• It's possible for students to develop misconceptions when using simulations, this may be an effect of scale (time or size) and the student cannot relate what is seen in the simulation to reality

  This was one of the reasons we felt it was important to have the option of running the experiments in real time (or in relative real time), so students gain a feel for the relative time events take to happen. (Particularly important in an experiment such as one looking at the effect of concentration on reaction rate). In cases where the the reactions occur too slowly or fast to simulate them in real time, the rate at at which time passes be increased or decreased. In such cases, we have deliberately designed the interfaces so the student makes the decision about how fast time passes.

• Students can be given more choice in experimental decisions

  In practice many experiments are carried out in the laboratory by students following a set of recipe-like instructions. In these resources, we have attempted to provide the learner with an opportunity to exercise as least as much (and potentially more) choice in the decisions they make in a practical experiment. So for instance, the SQA Prescribed Practical Activity explicitly states volumes of reagents to be used in an experiment, but in the real world the experiment will still provide valid results if different volumes are used. The same applies in the simulation. Potentially though,interfaces can be easily redesigned to provide even more choice. (Though of course the degree of choice must suit the level of student involved)

• Students can have access to experiments when there is a shortage of equipment or time

  Provided adequate pre-instruction is given, they can even have access to experiments without the presence of a teacher.

• They can provide data for students to work on if it is not possible to perform and experiment

  This can be useful for experiments which take too long to perform during a laboratory session or in cases where a student experiment has not yielded adequate data.

• They can allow the performance of experiments which would not otherwise be available because they are too dangerous

  However, note that there are objections to doing this, at least with some pupils. (See below)

• They allow mistakes without cost or damage.

  It is important to provide appropriate feedback when mistakes are made

• They have potential uses outside of direct replacement of practical experiments
  They can be used as:
  • As preparation for the student in advance of the laboratory exercise,
  • A simulated experiment (or a variant of the real experiment to avoid direct replacement)
  • For revision,
  • To provide practice in experimental design.
• Lab packs These simulation resources could be used in conjunction with other resources to provide a lab pack that might also include:
  • theory and background,
  • information on equipment and safety,
  • data books,
  • formative assessment for the student to check their understanding,
  • summative assessment for the teacher to check the student's performance.

The reactions simulated in these resources are real reactions which are suitable for use in laboratory practical experiments for students. Given the nature of simulation produced by JeLSIM, its fairly easy to change the values of the variables governing the behavior of the reaction ( see the training section) and to simulate different reactions. It was however felt by some that simulation of real, dangerous reactions would not be advisable as students might not realise they were dangerous. It was also felt that simulation of imaginary reactions might confuse students. What's your opinion? Mail rct@jelsim.org

1. Magin D and Reizes J (1990), Computer simulation on laboratory experiments: the unexplored potential, Computers in Education 4 (3), 263-270

this page was last updated April 7th 2003 :RCT
© 2003 Jelsim Partnership