Replicating research in science

[Hunter]

I've seen a LOT of science books talk about the importance of carefully writing the materials list and procedure, because in "real" science, being able to replicate an experiment is important.

 

This is the first activity I've seen though that has the students actually attempting to replicate other experiments.

 

http://sciencespot.net/Media/consumerchall.pdf

 

Is this an important part of learning the scientific method, do you think?

[MIch elle]

If you want to know how scientists write articles, which are taken from their research/notebooks, then go to the scientific journals where they publish and see how most of them are set up.

 

Here's one: http://www.abrf.org/Committees/JBT/Publications/JBTInstrforAuthors081104.pdf Scroll down to page 3 and look at "TEXT"

Edited November 28, 2010 by MIch elle

[regentrude]

I've seen a LOT of science books talk about the importance of carefully writing the materials list and procedure, because in "real" science, being able to replicate an experiment is important.

 

This is the first activity I've seen though that has the students actually attempting to replicate other experiments.

 

http://sciencespot.net/Media/consumerchall.pdf

 

 

 

I clicked on the link and viewed it - but did not see where they are re-creating somebody else's experiment. Am I missing something?

 

Is this an important part of learning the scientific method, do you think?

 

WHAT is?

A description of setup and materials? Yes, this should be accurate enough so that somebody else can reproduce the exact same procedure.

[Hunter]

Hmmm... I guess it is just challenging claims, not reproducing experiments. I see as I study it further :-( I think it could be tweaked though, using products that claim "taste tests..." if the student wrote the company for how the tests were conducted.

 

My students work in research teams (2-4 students) to challenge the claims of products available to consumers. From paper towel advertisements to powerful battery claims, my students take the lead in their learning and investigate their world using the scientific method

 

http://sciencespot.net/Pages/classgen.html

[Nan in Mass]

My husband designs experiments. He says the procedure and equipment part are important if you are going to hand the experiment to a lab technician or an intern or grad student to carry out for you. It is also needs to be detailed enough that somebody else can repeat it. But he says that often times, if you are just trying something yourself rather than doing a formal experiment, you write it up in much less detail. Then, if your activities lead to something, you might write up a formal experiement in more detail.

-Nan

[Hunter]

That sounds better! I used to let my son slack a bit with this part, so he could focus more on the research, and the cyclical nature of doing the experiment several times, each time at a higher level. But I used to feel guilty, and was corrected about it several times by an online friend with a scientist husband.

 

It was very confusing to me for the student to be cautioned so much about completing this step flawlessly, but to never be involved in replicating an experiment themselves :-0

Edited November 29, 2010 by Hunter
Spelling

[regentrude]

In actual research, the scientists does keep detailed notes about the important things of the setup. Of course he does not list all materials for each experiment- he has built his (often very complicated and expensive) apparatus and uses it for all kinds of measurements. He will, however, take meticulous notes about all the variables involved in the experiment that could have any bearing on the outcome: temperatures and pressures, detailed information on the sample he studies (size, thickness, composition, weight, procedure how sample was created etc).

During the experimental work, these information is constantly collected and saved in a lab notebook (although I suspect that some people nowadays would keep them on the computer).

As Nan said, the formal writeup happens when the results are prepared for publication. (A paper in experimental physics might list such-and-such apparatus, at such and such temperature and pressure, explain in detail the process of sample preparation - you would NOT find a list of every single screw, bolt or piece of foil. These details would, however, be available from the scientist upon inquiry.)

One important aspect about reproducing experiments is that the person who originally carried out the experiment may want to go back and verify data, or change a different parameter (something that turns out necessary often not until the manuscript for publication is prepared and some more data are required). Then it is essential to have meticulous notes so you can be sure you are only changing the one thing you intended to, and not a number of other factors as well.

[Hunter]

...Of course he does not list all materials for each experiment- he has built his (often very complicated and expensive) apparatus and uses it for all kinds of measurements. He will, however, take meticulous notes about all the variables involved in the experiment that could have any bearing on the outcome: temperatures and pressures, detailed information on the sample he studies (size, thickness, composition, weight, procedure how sample was created etc).

 

Hmmm....so this makes me think that anyone who is having a child focus on a skills vs knowledge curriculum, should have the child develop a "lab" of their own, even if it is portable and made up of mostly common household items. But that the child should be using the same brand and size of drinking straws for each activity/experiment for example.

 

Very interesting!

[regentrude]

Hmmm....so this makes me think that anyone who is having a child focus on a skills vs knowledge curriculum, should have the child develop a "lab" of their own, even if it is portable and made up of mostly common household items. But that the child should be using the same brand and size of drinking straws for each activity/experiment for example.

 

 

 

Yes. it is very important to be aware of WHICH variable one is changing and to make sure that everything else stays exactly the same. Otherwise it is impossible to decide which quantity did have which effect.

 

The first lab experiment my DD did was in 4th grade and used just household items. It was a simple pendulum, she investigated the effect of mass, amplitude and length of the string on the period. She learned a lot about keeping notes, making sure to vary only one variable, doing statistics for her data (i.e. multiple measurements, averages, error estimation).

It does not take complicated lab equipment to develop these skills.

[lisabelle]

I thought it might be helpful for me to share what information needed to be in my lab notebook last year when I was taking Organic Chemistry:

 

Materials Used consisted of a list of all the chemicals used in the experiment with a description of the color and other physical properties (including scent), the strength of the chemical and the MSDS data.

 

Before the experiment was conducted I had to draw a flow diagram of every step that should happen along the way.

 

I did not have to list the pieces of equipment used in the Materials section, but their set up needed to be described in my flow chart and my observations had to include pictures of the various set ups, with the individual pieces of equipment labelled (ring stand, 5 mL Erlenmeyer flask, tubing, ice bath, etc.). If we were using an instrument, like NMR, we had to draw a picture of that instrument--nothing fancy, just basic box with where the sample would go, where the various knobs were, etc.

 

I think it's worthwhile to have students build up to that level of description in their lab reports. If nothing else, it's sharpening their observation skills and helping them to realize they should take nothing for granted about what they're doing and what their readers previous knowledge is.

[Nan in Mass]

Thank you!

[swimmermom3]

This is an excellent thread that addresses some of the issues that have plagued our home science work. When I pulled my oldest son from school, his science teacher was dismayed because my son enjoyed science and she wasn't sure how I could provide the same experience that a trained science teacher with a fully equipped lab could provide. I felt the same way and went a bit overboard to try and prove her wrong. My son loved science at home because we could do more experiments, but my insistence on a "full" lab report for each and every experiment nearly killed off his love for the discipline.

 

My husband designs experiments. He says the procedure and equipment part are important if you are going to hand the experiment to a lab technician or an intern or grad student to carry out for you. It is also needs to be detailed enough that somebody else can repeat it. But he says that often times, if you are just trying something yourself rather than doing a formal experiment, you write it up in much less detail. Then, if your activities lead to something, you might write up a formal experiement in more detail.

-Nan

 

I just followed the instructions for lab reports that came with the curriculum that we used at the time. It would never have occurred to me to research and find out how "real" scientists operate. It would be interesting to have a lab report thread that featured the feedback and experience of the scientists on the board. I know we have several and there are even more spouses. But then there is also the reality of what is done in the field and what you can expect from a 7th grade boy who has several other subjects to attend to as well.

 

That sounds better! I used to let my son slack a bit with this part, so he could focus more on the research, and the cyclical nature of doing the experiment several times, each time at a higher level. But I used to feel guilty, and was corrected about it several times by an online friend with a scientist husband.

 

It was very confusing to me for the student to be cautioned so much about completing this step flawlessly, but to never be involved in replicating an experiment themselves :-0

 

But Hunter, if they are following an instructor's experiment in a text book, aren't they in effect replicating an experiment? Often times a student will be required to repeat an experiment more than once to check the consistency of their results. Some of our most instructive labs happened when we had to assess why a variation occurred when it shouldn't have. Or am I misunderstanding what you are asking here?

 

Hmmm....so this makes me think that anyone who is having a child focus on a skills vs knowledge curriculum, should have the child develop a "lab" of their own, even if it is portable and made up of mostly common household items. But that the child should be using the same brand and size of drinking straws for each activity/experiment for example.

 

Very interesting!

 

I still forget about product consistency with supplies pulled from home. We usually try to make a note in the report.

 

We have come to a place where we do two separate types of lab reports. The first one is the "official" painful one that is done according to the standard format. When we do these, the focus is on the skill of writing a lab report and less on the science itself. We will do about one of these to four of what I would call a basic write-up. We don't list materials if we are following a written experiment. We only note any changes we make to the equipment. The focus is on inference, observation, and reasoning.

 

Perhaps this is not the "right" way to do it but we get a lot more science done this way.

[swimmermom3]

I thought it might be helpful for me to share what information needed to be in my lab notebook last year when I was taking Organic Chemistry:

 

Materials Used consisted of a list of all the chemicals used in the experiment with a description of the color and other physical properties (including scent), the strength of the chemical and the MSDS data.

 

Before the experiment was conducted I had to draw a flow diagram of every step that should happen along the way.

 

I did not have to list the pieces of equipment used in the Materials section, but their set up needed to be described in my flow chart and my observations had to include pictures of the various set ups, with the individual pieces of equipment labelled (ring stand, 5 mL Erlenmeyer flask, tubing, ice bath, etc.). If we were using an instrument, like NMR, we had to draw a picture of that instrument--nothing fancy, just basic box with where the sample would go, where the various knobs were, etc.

 

I think it's worthwhile to have students build up to that level of description in their lab reports. If nothing else, it's sharpening their observation skills and helping them to realize they should take nothing for granted about what they're doing and what their readers previous knowledge is.

 

How long on average would it take you to create a flow chart?

 

If you were working on building a student's skills up to that level of accomplishment, how would you proceed over a period of say 7th grade to 12th grade? In those earlier years, you are often dealing with students whose fine motor skills (especially boys) are still developing and for whom vast quantities of writing are painful and discouraging.

 

We have done drawings in our lab reports, but I don't think we have ever done flow charts. Can you hear my wheels spinning? Do you have a link to a sample one?

[lisabelle]

How long on average would it take you to create a flow chart?

 

If you were working on building a student's skills up to that level of accomplishment, how would you proceed over a period of say 7th grade to 12th grade? In those earlier years, you are often dealing with students whose fine motor skills (especially boys) are still developing and for whom vast quantities of writing are painful and discouraging.

 

We have done drawings in our lab reports, but I don't think we have ever done flow charts. Can you hear my wheels spinning? Do you have a link to a sample one?

 

The experiments probably comprised a good 10 pages of text. If I had pre-read the experiment at home so that I was familiar with it, I could chunk out a flow chart in the hour between lecture and the start of lab. I actually found it much easier to do the flow chart than to write the narrative of what was to happen in lab (which was written during the lab itself). And the flow chart was such a handy thing to refer to over the course of the experiment--I viewed it as kind of a recipe for how the lab was supposed to work.

 

To start with, in writing observations (and this has more to do with chemistry than the biological sciences), I would recommend drawing pictures of the experimental set-up. I wouldn't require labelling as long as a person reading can get a general sense of what's what. Maybe include the capacities of the glassware used. I would be sure they note the important things—what is added in what order, any changes in state, what the final product looks like. My observations had to take the form of a narrative, but initially I’d settle for bullet points.

With chemicals I would only require descriptions of anything that wasn’t generally known. Like, I wouldn’t expect Table Salt (NaCl): white crystalline solid, odorless. Though I’d expect the chemical formula. I wouldn’t worry about MSDS data; most things that we use at home for science aren’t going to be hazardous. For the occasional thing that is, I wouldn’t require it be written down, but I would expect that a student know exactly what to do on exposure before using the chemical.

I think, as our students get older, their labs will tend to come with more and more complex questions at the end, whether they’re those that are provided in a laboratory text or whether they’re our own questions we have of our students. Those can provide a good guide to what kinds of things they need to be observing and recording in their notebooks. They can gradually work toward being organized enough to make room for a table when it’s part of an experiment (time v. temp., for example) and adding graphs. Writing a narrative while working is a good goal as well. It’s actually, as I found, kind of a challenge to organize thoughts into complete sentences while watching over an experiment.