Data collection and processing.

2nd aspect of study!!!

Data collection• In the method we had made sure to record data that shows more than

just one trial. In data collection you study this recorded data through calculations or other methods to reach a conclusion.

• Please organize your data into tables… this is not where you show a graph.. You only tabulate so you can derive what to do with the information.

• This is like collecting all the clutter and organizing it into a mind map. • Label your table explaining the purpose of the data you’re collecting. • Number your tables… consecutively throughout the report. • Qualitative data is as important as quantitative data so record the

physical characteristics of substances and their changes whether hot or cold.

• A measurement without units is useless!!!!!!

Data collection

• Even if you write the units in the title of the table on top, write it after every number in the table as well.

• Format – Initial velocity (cm/s) • All measurements have uncertainties and you

must indicate them in your data table • This is where you need to be careful because all

data you record must also be put in your log books (WAIT! What’s that?????)

Sample data collectionData table for distance covered by the ball and corresponding time taken:

LOG BOOK ???? • IB demands a log book for all the work you have done. Make your notebooks

today. These are not formal notebooks where you need to show neat hand writing or proper presentation of work. This is a place where you collect lab reports, show your rough sketching, discussion of ideas, collection of data.

• This is the only way to prove to IB that all the work that has been done through out has been originally your work and you have done it the way IB requires you to do.

• This is a must and should not be avoided or copied under any circumstances. • Please don’t fool yourself by copying it off a friend at the end moment and

getting it checked by your teacher. This is a statement of authenticity so there is not point trying to play it smart. IB will catch you no matter how smart you are.

• It would be best if you present your logkbook in a way that shows the development of your experiment at all stages.

I’ve collected data.. What next? Now you process this data… 1) Raw data needs to be now calculated – this is the part where you take

raw data and transform it into results. 2) Show calculations that numerically prove the results of your experiment.3) Sometimes you will need to make a graph to make your calculations

clearer before you infer the results4) Always remember to study the relationship in your graphs – don’t just say

this is the graph showing the development of yeast in 10 days.. Say this is a graph showing the rate at which the yeast developed during an interval of 10 days.. In respect with the temperature changes that took place at a gap of every 18 hours. (remember… DETAILS)

5) Your calculations must be presented neatly and in a coherent organized matter.. You do get marks for presentation of data.

6) Please remember to mention all the units carefully in the calculation. Don’t do it in a hurry and check at least 3 -4 times before you submit it to your teacher.

Calculations

• If you have to calculate the percentage or any particular aspect for let’s say 10 readings.. Then show the calculations for 2 -3 readings and say the rest will be done similarly. You must however show these calculations in your log book.

• When calculation an average value from repeated trials, don’t average the raw data. Calculate a result from each trial and then average the results from the calculations.

• Pay attention to significant digits! Accuracy is important. You can’t decide to round of a .05 to 1…or .8792 to 088… NO

• It is a good idea to use five digits after the decimals before rounding off the last digit.

What do calculations look like?

for the first reading,

Presenting your results.

• You will be using tables and graphs to present your results

• Should have appropriate title, table number, units etc• You can use different softwares to make your graphs. • The axes of the graphs must be clearly labeled with

variables and the units used. • Graphs must have a best fit line with a slope. • After you graph or tabulate your results, you need to

write a short paragraph explaining what the graph tells the reader. (The best fit line in graph 1 confirms:….)

Uncertainties in data?• Report a level of uncertainty for all data• When calculations are made with already some uncertainty – report the

errors that might have occurred in the results• To show uncertainties on the graph – show error bars for at least one axis• Do not connect the data points with the errors – only graph the best fit

line• If you’re data doesn’t hit the line with it’s error bars that means there is

some significant error in the experiment or the recording of the data. • After presenting your data – you must discuss the presentation and

explain your idea behind presenting the data in a particular manner. • Please make sure that your graphs, tables, bar graphs are not that of a

primary level appearance – show a complex graph which shows an intricate understanding of the results.

Conclusion and evaluation

• After you have presented your data and the results from your experiment. You need to discuss and re-state the result of your hypothesis with all the errors and uncertainties.

• You must explain your conclusion in terms of that data that you calculated.

• Show a possible percent error while doing the calculations• All your evidence and logic behind the experiment must be

stated in your conclusion • Your conclusion will be a small paragraph only stating the result

of the experiment in regard to the hypothesis. • Evaluation is where you would discuss the findings and their

meaning.

Limitations• Note all the limitations in the conclusion that might have occurred due

to errors or uncertainties. • You must discuss how confident you are about the results of the

experiment• Also is there a possible interpretation to your results? Could there be

another way of looking at it? - show the understanding for something that you might not have done in your experiment but are aware of.

• Your emphasis should be on the section that shows systematic errors and then show how these errors can be improved.

• Suggest feasible options to remove uncertainties from your experiment. • The most important part of stating the limitations is also discussing the

strategies for improving them.

Scope

• After you complete all of these formalities you must mention the scope of your experiment.

• How could this experiment be carried forward? If you had different equipment, would the experiment be easier to perform? Will there be lesser errors in case of different equipment? Even if the experiment is repeated exactly like yours, is there a scope for finding different results? Could you conduct the experiment in any different way in your knowledge.

• All these aspects must be discussed in detail.

Bibliography

• What kind of resources do I put in a lab report?

• Internet sources where you’ve taken background information from.

• Textbooks where you’ve taken information from.

• Calculation manuals (in case you use any)