2008 Lab Write-up Guide for Grade 10

The following outline is for a full lab that you design. For other exercises, follow your teacher’s instructions. The information below will help you on the applicable sections.

Standard 9 Designs experiments: Constructs research questions, hypotheses and procedures

1. Problem Question or Aim: This will be a question that includes both the independent and dependent variables (see definitions below). You should include the measurement technique of the dependent variable; do not state that you are measuring rate of something. The hypothesis is a possible answer to this research question, and the actual answer that you discover should be in your conclusion.

2. Background (only include when teacher directs): Include here any information that helps the reader understand what you wanted to accomplish, and why. Research is needed to do a good job but put all information in your own words (read, take brief notes, put texts away, write it up). Cite your sources for anything you didn’t already know. (website or book title, date). You can include previous experimental results, but cite sources.

3. Hypothesis Predict an outcome based upon the background information. The usual format is ÏF …something is done and it affects the object, THEN….. Avoid use of “I think….” Include a scientifically valid reason for your hypothesis – if you don’t explain the hypothesis then this section is incomplete.

4. Variables Description A valuable way to make sure you include all your variables appropriately is to use a table like this before doing the experiment. Include it in your final report.

Independent Variable (what you are changing) / Dependent Variable (what you are measuring or what is affected by the variable that is changed) / Controlled Variables (those factors that need to be held the same in each trial so that you get a fair test)

5. Materials List

Just a list of materials – include quantities and sizes (include concentrations of any solutions). Labeled diagrams of complicated apparatus or arrangement of equipment help in understanding and force you to think through the experiment before you perform it.

6. Procedure

  1. In point numbered format, summarize step-by-step what you will be doing to carry out the lab.
  2. These should be in your own words, and should include ALL details as these are your directions.
  3. The steps should be clear enough for anyone else to follow exactly as the lab was done the first time.

Standard 10: Collects and processes data

Make a data table before the experiment. Fill in your data using ink. Tables MUST have a descriptive title, units for each column, margin of error in any columns where measurement occurs (+/- ½ the unit of measurement), columns for any calculations you will have to do, and the appropriate number of significant digits (all entries much contain same number of decimal places).

Sometimes there are uncertainties in collecting data that makes the numbers you collect suspect or less accurate. Describe any errors or uncertainties just under the data table. If you have used the Vernier sensors and a graph is produced for you, you should include a print in your final report.

You will also manipulate your data through various calculations or graphing activities in most labs. Calculations with the equations and its variables should be included in the report, including at least one example for each type. Do not use more significant digits in your answers than in your measurements. Graphs must include descriptive titles, units, be in proper scale and should be either hand drawn or be from a graphing program as indicated ahead of time. Usually the dependent variable goes on the Y axis.

Standard 11: Draws conclusions and evaluates experiments Consists of 2 parts, which must both be included for full marks. Divide your CE up into paragraphs – that makes it much easier to read!

1. Conclusion:

  • Restate the results. Repeat the relevant data or observations that led you to that conclusion.
  • What is the answer to your problem statement or aim?
  • Restate the hypothesis and compare your conclusion to it.
  • How reliable (accurate) are your results? Why? Is data accurate (close to the true values) and precise (measurements taken to the proper significant digit)?
  • Explain your conclusion and results in terms of scientific concepts; we will be looking to see if you understand the events that occurred in the lab.
  • Do the data follow current scientific knowledge, or were there errors that leave your conclusion questionable/inaccurate? You can mention those problems here but give details below.

2. Evaluation:

  • What errors did you find or perform during the experiment?
  • What use is doing this lab and how might the data be used? Are there further experiments that can be performed or did the data suggest other avenues to explore?
  • What anomalies (unexpected results) were there and where were the errors? How did those affect the data? Use the following table to help you describe those errors and how to fix them:

The error or problem encountered / How that error affected the data / A suggestion for improvement
Heat energy from the reaction was lost to the surroundings / The maximum temperature recorded was lower than it should have been / Insulate the reaction vessel; use a polystyrene cup + lid instead of a glass beaker

Note: Never say “Measurements could have been more accurate…” Or “we could have worked harder/paid more attention to what we were doing.” Those are not valid evaluation statements and you are wasting paper.

Some things to avoid:

- hypothesis, procedure, and conclusion be about different things. These should be consistent & complementary.

- not recording data that occurs. In analyzing data you should not include those values that are way off the average (outliers); BUT that depends on your experimental setup.

- taking too small a number of samples or trials. The more, the better.

- recording data that did not occur. DISHONEST!!!!

- only working on the lab write-up the day before it is due. What happens if you have questions? Or the electricity goes out or you get sick? Do all work as soon as possible.

- working closely with your lab group. Same work, tables, phrases, etc is cheating. Discuss but write separately.