So far this semester, we have spent a lot of time discussing various forms of uncertainty that arise in an experiment. Within that context, we have seen that way data is taken as well as how an experiment is designed can have a large impact on the uncertainty, something we look to minimize where possible. This has been especially true when measurements have been taken in different ways, yet still compared together (i.e., can we compare two people's angular measurements if they used different methods or definitions of the angle?). Therefore, being clear and unambiguous as you document your experiment is important.

In this workshop, you and your group are tasked with developing a procedure to measure how one variable affects another. You will be responsible for determining an efficient design as well as documenting a procedure for others to follow. You will then try to reproduce another group's design, critiquing their work based on your ability to reproduce it. In this way, you will also be developing a critical look on various designs and work done by peers. By supporting each other's work, we not only help them improve, but will be able to improve our own work, too.

Like everything else in this class, documenting effectively is a skill to be developed. That's why we have dedicated a full workshop day to documenting experimental design. This exercise, combined with the feedback you've received about your notebooks, is intended to give you the supports you need to document your work effectively throughout the semester and beyond.

In order to be productive in class, it would be helpful to research before class:

  • Reproducibility of experiments
  • Confirmation bias
  • Ethical considerations when conducting and documenting experiments (<https://goo.gl/rFiFAl>, especially section 3a)

The National Academy of Sciences has published a book discussing responsible conduct of research. While this goes beyond the scope of this workshop, anyone that hopes to conduct scientific or medical experiments should be aware of it and its content. It can be found free here: <https://goo.gl/dNhzlc>

Part 1 – PB&Js

As part of your homework, you were asked to submit a procedure for making a peanut butter and jelly sandwich. Let's take a look at what some of those procedures look like when picked up by another person. To best engage with the discussions, it would be helpful to consider:

  • Are there various ways to interpret instructions?
  • Can you develop procedures that are clear and unambiguous?

Part 2 – Documenting Experimental Design

As seen in Part 1, how someone reads somebody else's procedure will depend on their background and familiarity with the task. Accordingly, we ignore certain details in our work (i.e., you don't define every word before using it, right?). However, it's not always known which details can be assumed and which are important to convey, so being concise yet unambiguous is not simple.

Each group has the material to conduct an experiment relating one parameter to another. Using the materials on your table, you and your group will develop an experiment to determine either:

  • How the length of a spring depends on how many masses are added to it,
  • How the angle of a metal strip depends on how many magnets are placed on it,
  • Or how the time it takes a ball to roll down a chute depends on how many blocks are under the chute.

*Note, you do not have to take data or present data in this workshop, but rather develop a method that would be appropriate to obtain data and document it accordingly.*

Record your procedure the same way you would do so in your lab notebook. Your procedure should be clear and detailed enough so that someone could reproduce your experiment, including collecting very similar data. Again, there are two likely populations – yourself and other scientists – who would use your notes in a research lab, and considering them help define what is necessary. As such, your notes should be clear enough so that:

  • You can follow your notes again months or years down the road.
  • Another scientist could take your notes and reproduce your results.

Therefore, when documenting your procedure consider:

  • Have you included enough details that you won't rely on memory if trying to conduct this experiment again in the future?
  • Have you considered the clarity of your work to prevent ambiguity in interpretation?
  • Is your experiment effectively designed, capable of obtaining the data you are looking for?

Part 3 – Critiquing Peers Constructively

As mentioned, having your notes clear enough for another to reproduce your results is an important part of research. Rotating around the room, your group will now try to replicate the experiment another group laid out. In doing so, not only will you be able to give meaningful critique that helps your colleagues, but hopefully you will also recognize some of the areas in which you could improve.

With your group, attempt to conduct the experiment another has developed and critique their work. It is important to be constructive, so please give detailed results when writing up your opinions of their work. While discussing what the group did well and where they could improve, please consider:

  • What did you like about their documented procedure? What do you want to bring with you for your future work?
  • What confused you about their procedure? How could the group have improved their documented procedure?
  • From the procedure provided, did you feel that there were multiple ways you could have conducted the experiment? Do you feel like you conducted your experiment in the same way the other group did?
  • Could the group have provided less details or been more concise without losing clarity?
  • Could you have developed the procedure differently? Did the group choose a method that would obtain meaningful results?
  • If you were to pick this up months later, would you be able to reproduce what you did today?

At the end of the day, we will collect your notebooks for feedback. We will be focusing on ways you documented your notes and your thoughts. We also will be emphasizing the way you constructively critique your peers and the reflectiveness of your comments.

  • wks2.txt
  • Last modified: 2019/08/13 16:47
  • by rachel