Lab Report How to write a good biology lab report.

[Mahuta ♥]

Okay, so I found a bunch of notes I took when my teachers were giving us IA tips and format..etc. Some of the below I had to copy of the board, so you may find these in the books.

So, Biology IAs should follow this general format:

DESIGN

1)Research Question

2)Hypothesis/Predictions

3)Variables

4)Apparatus

5)Method/procedure

DCP

1)Collected data

2)Data processing

3)Data presentation

CE

1)Conclusion

2)Evaluation

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Design

Research question:

This should be a clear focused question that says exactly what you are investigating. It shouldn't be too long and it must include the dependent and independent variables.

Eg. What is the effect of pH on the activity rate of salivary amylase?

Dependent variable: activity rate

Independent variable: pH

Hypothesis:

This is a paragraph or two where you explain your research question. You are going to say something like:

"Salivary Amylase is a an enzyme that digests starch into di- and monosaccharides. Since it's a salivary amylase, the enzyme works best at an alkaline pH of 7, in other words, the optimum pH is 7. At this pH, the rate of amylase activity will be at it's highest. A pH that is much lower (very acidic) or much higher (very alkaline) will denature the enzyme permanently (specifically the active site), and the enzyme can't function anymore. The activity of the enzyme will decrease as we increase or decrease pH."

You may also want to include a graph to show this if this possible.

Variables:

A list or a table that include:

-Independent variable: this is the variable you're changing. In the example above, the pH.

-Dependent variable: this is what changes when you change the independent variable. Eg. Activity rate.

-Controlled variables: these are all the other variables that must be kept the same in order to get an accurate results. For example, Temperature, pressure..etc.

Apparatus:

This is the list where you include everything you are going to use. Make sure you don't forget anything. My teacher always told me to include a diagram of the apparatus, so you may want to add that too.

When listing the apparatus, be specific:

1)'A beaker' wont work, you have to specify the type and the volume. Same for any other apparatus of this sort.

2)When listing chemical substances like enzymes or starch solutions. Include the volume and the concentration.

3)For Solid substances used, include the mass in 'g'

4)When mentioning the thermometer, you may want to say it goes from -2C to 100C just to be specific.

Method:

I always prefer the method being in a list format rather than a paragraph. It makes it much easier to read and understand. I would advise you to not use the first person. For example if you want to say "I will measure 50ml of starch solution into a beaker" you should say "Measure 50ml of starch solution into a beaker"

Please make sure you include every single step, don't miss one because it seems like an 'obvious' step!

Also make sure that your method controls the controlled variables and allows the collection of raw data.

After finishing your design, take a look at the table below (from the syllabus) to make sure you didn't miss anything:

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Data Collection and Processing (DCP)

Collected data:

This is normally given in one or more tables. Make sure your table is clear and easy to read and follow. Trust me, it makes a difference. Do not forget to include the units at the top of each column in brackets and the error!

Here's an example:

Data processing:

Data processing is where they want you to do something with the data. Find an average, do one of the hypothesis test, calculate the standard deviation...etc. It normally depends on the experiment.

Errors/uncertainties:

This is the calculation of the % error in your experiment which you're going to discuss in CE.

The uncertainty of each apparatus should be printed on it. If it's not, then the uncertainty is the half the smallest division. For example, a ruler that with 0.1cm division will have an error of +/- 0.05cm.

Data presentation:

This presentation should be of the raw data and the processed data if possible.

Bar graphs and line graphs are one of the best way to present a data in most cases. A pie chart or a scatter graph may also be used. When adding the graph, make sure it has a title, labelled axis and legends. If you are for example investigating something at two different environments or situations, you should have a graph for each and then a third graph with the both, to show better comparison. In most cases, you are going to have to do at least 3 or 4 trials, include the graphs for each, then a final one of the average results. When appropriate include the uncertainties in the graph.

Please make sure the graph/chart is suitable for your type of data before using it.

Here are examples:

Bar Graph:

Pie Chart:

Once again, take a look at the criteria for a last check:

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Conclusion and Evaluation (CE)

Conclusion:

The first point about the conclusion is that it should directly relate to the hypothesis. In other words, your conclusion must restate and discuss the hypothesis. You are not going to say why the results weren't accurate in this section. You're going to do discuss your results. Does it support the hypothesis? Were you predictions correct? Make sure you mention them again. I read this in one of the documents it got, and many people make this mistake: when talking about a hypothesis you're talking about whether the results support or refute the hypothesis, not prove the hypothesis.

In your conclusion, make sure you discuss the graphs, the charts..the data processing..etc.

Evaluation and improvement methods

I would organize this part in this way:

1st paragraph: the weaknesses and limitations.

In other words, all the possible reasons you could think of as to why your % error is too big (if that applies), why you results didn't perfectly support the hypothesis, why you results weren't accurate...etc. So basically, you're going to talk about all the weaknesses in your design and the effects these weaknesses had on the results. When mentioning the possible errors, I suggest doing it in bullet points because like I said they're much easier to read and understand.

2nd paragraph: improvements:

This is basically the "The errors above could be avoided next time by.....". Then just start suggesting all the things you would do differently next time to get better results, for example:

1)Repeat the experiments more than x times.

2)Control temperature and pressure more carefully.

3)Try to reduce human errors.

4)Use more accurate apparatus for volume measurements.

and so on.

Criteria table:

EDIT: Criteria tables added.

[Markee]

can this apply for Chemistry as well? Like, exactly for chemistry too?

[Mahuta ♥]

I would say very similar yes. Since the guide my teacher was referring to when he talked about is was for all experimental sciences. But I made this a 'biology one' mostly because that's where my interest is.

[Markee]

I would say very similar yes. Since the guide my teacher was referring to when he talked about is was for all experimental sciences. But I made this a 'biology one' mostly because that's where my interest is.

But it is safe for me to follow this word for word with my Chemistry coursework?

(This is great as well for my Extended Essay on Biology)

[Mahuta ♥]

Yes it is safe.

And yeah, my chem EE supervisor told me an EE in an experimental science is basically an extended lab report.

So basically for the EE you are going to have an 'Introduction' before the hypothesis which should be long. Then make everything a little more detailed..and dada! you have a biology EE.

P.S This is how my teacher told me..including the 'dada!'

[Cool Beans !!]

Should there be a section for background information in the design? It seems that on this list the background info is mixed in with the hypothesis, but I was told I should have a section for background info.

[Mahuta ♥]

If you want to make it long, then yeah okay. But you don't have to, the things you need to 'introduce' are the things you're going to talk about in your hypothesis, so they might as well be in the same paragraph.

[Hinuku]

Hi, what are the criteria for Data Collection in a laboratory report? I have no idea what to include in mine except for the data collected which are photos so no text whatsoever.

[Mahuta ♥]

Here's the criteria table for DCP:

What do you mean only photos? If it's like photos of certain things before and after, then you can make a table for that. Doesn't always have to be numbers.

[Guest Soiboist]

I have a question concerning Evaluation. Wouldn't it be far more convenient to write the improvements directly after that you have presented a limitation, so that the examiner would more clearly be able to see why the improvement is relevant? Then you could split up the paragraphs after number of limitations/improvements rather than having one paragraph for all limitations and one for all improvements.

Additionally, we never included Apparatus, Variables or Method in regular lab reports (just for design labs), is that wrong? I'm not worried though, as they were just practise labs.

[Mahuta ♥]

For your first question, certainly. You can do it any way you want as long as it's coherent and easy to follow.

For your second one: Very wrong! Variables must be included, let alone the method! In fact, the variables and method both take one of the 3 aspects of the criteria. Also, we were told to always always include the list of apparatus and not miss a single thing we use.

[Guest Soiboist]

Obviously we did include independent and dependent variables through the aim, and on second thought possibly the controlled variables as well. Though I am sure that we did not include neither apparatus nor method. It surprises me as my teacher usually is very solid, but we might have skipped those for practise purposes. We included them for writing design labs, so I would believe she knows about them.

Thanks for your help anyway, I'll ask my teacher about it if we're not supposed to do it for next lab either.

[dessskris]

@Hinuku if you didn't make any quantitative data collection then your pictures are the only thing that you can put in your data collection.

@Soiboist actually the IB examiner doesn't care about your presentation/format of the lab report. I've seen a lot of labs whose CE is put under only one Heading which is Conclusion&Evaluation and everything is put all over this section (so it's like what you want, the improvements can come after each limitation). I've also seen a lot whose CE is split into Conclusion, Limitations and Improvements (so 3 sections). both are acceptable and I myself would go with the first method (everything under the same heading).

EDIT: whoops! didn't see Mahuta's response on the next page.

and Soiboist are you even in IB yet? or are you in IB MYP? you need to list your variables and apparatus and write the method under separate headings so it's easier for the examiner to mark. the variables must be listed in design labs, but in DCP/CE you don't need them.

Edited May 15, 2011 by dessskris

[jess1ca]

I'm confused about how specific the variables/ hypothesis should be.

For example, which is better:

Independent: light intensity

Dependent: rate of photosynthesis

If the light intensity is increased, then the rate of photosynthesis will increase, because....

OR

Independent: wattage of light bulb, which changes light intensity

Dependent: Amount of effervescence produced, showing the rate of photosynthesis

If the light intensity is increased by increasing the wattage of the light bulb, then the rate of photosynthesis, shown by oxygen production, will also increase, because...

I was told to keep the hypothesis at one sentence and I don't know how to do that without creating long, run on sentences.

[dessskris]

the first one.

usually in my designs, I put a "Method" section before my "Procedures" where I explain "Method of data collection" and "Method of controlling the controlled variables".

in my "Method of data collection" I usually explain how to change the independent variable and how to record the dependent variable, so if you wrote:

Independent: light intensity

Dependent: rate of photosynthesis

in the "Variables" section, then in this Method of data collection you can explain how you change the light intensity (by changing the wattage of light bulb) and how you measure the rate of photosynthesis (from the Amount of effervescence produced).

[jess1ca]

Thanks Another question. Do I need to show calculations for mean and standard deviation in my data processing, or can I just make a chart of the values, graph it, and indicate that the data was processed using Excel?

The formula for SD and mean are pretty obvious, and I don't have any uncertainties in this lab that would be relevant to the calculations.

Edited September 4, 2011 by SmilingAtLife:)

[dessskris]

you need to show like the formula of how you find the average and std and then show ONE example for each (in your data processing) and then since you have LOTS of data, put a table for the rest of the data. but the formula and one example are necessary

[jess1ca]

Thanks again. How many sig. digs/ decimal places do we need for the standard deviation? The raw data is a counted number and the mean has 1 dp, 1 sig dig.

Edited September 6, 2011 by SmilingAtLife:)

[thebest]

How do I measure/write uncertainties for units? Like for if my timer is to 1 decimal place, what would it be? If it was to 2 decimal place what would it be ?.. Sorry, jst a bit confused.

[Mahuta ♥]

The uncertainty of each apparatus should be printed on it. If it's not, then the uncertainty is the half the smallest division. For example, a ruler that with 0.1cm division will have an error of +/- 0.05cm.

So if your timer is to 1 decimal point..say 0.1 seconds, then the uncertainty would be +/- 0.05 seconds. Similarly if it's 0.01 seconds then the uncertainty is 0.005 seconds That being said, almost every apparatus would have the error on it.

As to how it's written, just put it at the top of each column like shown in the example above.