Developing Online Physics Labs – The First Step

Online courses must encourage the learner to be cognitively engaged.   The instructor must also facilitate a classroom community that helps students learn the material and promotes constructive feedback. In addition to the challenges the generic online environment brings, physics students bring their own particular array of challenges:  misconceptions about how the physical world works, preconceived ideas about the nature of the course, and anxiety about completing laboratory investigations.  Instructors developing online physics curricula must factor all of these components into the design of their courses; this article will address some of the challenges in laboratory design for online courses.   

Laboratory investigations in an introductory physics class are designed to have many outcomes.  Some labs allow students to measure known constants.  Other labs allow students to develop an understanding of the relationship between their physical movement and motion graphs.  Still other labs allow students to verify specific laws that govern nature.  The question that arises when developing online laboratories in physics is: “How does one develop investigations that allow students to repeat these same experiences at home?”  Online students probably do not have access to the same computer equipment and investigative hardware available in a seated class. Such equipment is expensive and hard to keep track of, so instructors are faced with the double-edged problem of how to get the equipment to the student and how to teach them to use it.  However, online instructors should think carefully about what they are really trying to achieve in a physics lab.  Is it important that the students know how to use the stopwatch or is it more important for the student to understand the implications of the data collected?  The first step toward developing effective online physics labs is to identify the general learning outcomes students should be able to accomplish in any physics laboratory investigation.

Take for example this simple exercise:  hold a piece of paper and a book at the same height and drop them. Which one lands first?  The book does.  Many students believe that the paper falls at a slower rate because it is lighter.  Now take the paper and crumple it into a ball.  Repeat the drop.  They will both land at the same time – which is what they are supposed to do all of the time!  The weight of the paper has not changed, so why did it land at the same time as the book?  Students learn that the rate at which objects fall on Earth does not depend on weight but on the amount of air resistance acting on the object.  In this example the belief that lighter objects fall at a slower rate than heavier objects is a misconception that students typically have based on their daily observations; while the observation itself may be valid, the inference made from the observed outcome is based on a subjective selection of premises.

In any physics classroom, instructors seek to provide quantitative data that help correct any misconceptions that the student may have brought to class.  Another example involves a common lab designed to determine the acceleration of gravity by dropping an object.  The lab may be designed so that students drop objects of different masses and different shapes in order to prove that objects with negligible air drag in freefall all increase their speed at the same rate.  Using differently shaped objects allows the instructor to show students that the presence of air resistance explains why some objects do not fall at the same rate.

In the online environment, physics investigations can be designed to achieve the same outcome.  However, some sort of communication tool should be used in conjunction with the laboratory investigation.  Instructors could group the students in forums and have them discuss the results of their data or answer analysis questions as a group.  These activities could promote community building as well as allow the instructor to identify misconceptions and address them.

Data analysis is another goal of a physics laboratory investigation.  Physicists collect data to learn something about it.  Large amounts of data are better understood by graphing the data and determining the relationship between the independent and dependent variables in the experiment.  By understanding the mathematical relationship between two quantities, one can verify a particular concept.  For example, in lab students may discover that a 1 kg mass weighs 2.2 lbs, a 2 kg mass weighs 4.4 lbs and a 3 kg mass weighs 6.6 lbs.  Analysis of this data would suggest that mass and weight are directly related. 

In an online environment, students do not always have access to the equipment that exists in a face-to-face laboratory.  Incorporating simulations into the laboratory investigations is a viable and readily available alternative. There are a multitude of physics java applets available on the web.  These simulations allow the student to collect data.  Instructors can have students manually graph the data or use MS Excel to graph the data.  Excel is particularly good because students can easily perform data analysis by fitting different mathematical functions to the data.  It may be wise once again to encourage students to discuss the implications of the findings in a group or individual discussion forum. 

Moreover, a simulation can actually have an advantage over a face-to-face lab.  While actual labs are subject to the vagaries of equipment deterioration (due to aging or mishandling), misinterpretation of instructions leading to mistakes in setups, and the unwitting introduction of other environmental factors, simulated labs have only such shortcomings as they are designed into the program.  Often students’ misconceptions and apprehensions cause them to be skeptical of the class and lab environment, and a lab that does not produce the intended outcome due to such random factors can actually reinforce the students’ skepticism instead of disproving it.

The goal of all science courses is to teach the learner how to work collaboratively in a laboratory setting. More importantly, laboratory investigations should allow the learner to better understand the nature of science.  Even though we expect certain outcomes in an experiment, the data set we collect does not always support our hypothesis.  There are many reasons for this.  There may be experimental errors, calculation errors, factors that are not accounted for in the experimental design, or our hypothesis may be incorrect.  Learners should be expected to critically analyze why their results do not meet the expected outcomes.  In most real-world laboratories, what is most often the greatest discovery from a given experiment is not what went right, but is in fact the explanation of what went wrong!

Students collecting data on their own will often lack confidence in experimental design, data collection and analysis.  By requiring some sort of communication among students in the laboratory investigation, students can bounce ideas off each other and ask questions to clarify what they are doing. The instructor can design analysis questions that encourage the student to consider what was expected to happen and the factors that contributed to the actual results. Questions asking the student to relate events they have experienced in the “real world” can add another dimension of insight to the learning experience. 

Developing a general set of learning outcomes for any course is the first step in any course design.  When considering what laboratory experiences to include in an online physics course, the instructor should focus on developing more generalized learning outcomes rather than on attempting to duplicate the seated laboratory experience.  Laboratory investigations should therefore be designed in such a way as to accomplish the following three basic goals:  promote a better understanding of the nature of science, facilitate student’s proficiency in data analysis, and identify and correct misconceptions of physical laws students have developed from everyday experiences.  However, a corequisite to each of these goals is the incorporation of communicative activities among students so they can truly become active learners.