1. Read in advance the activity to be done, and arrive at the lab prepared for investigation.  You will usually need the entire period for performing the experiment.

2. FOLLOW ALL INSTRUCTIONS CAREFULLY.  "One minute" means one minute by the second hand on a clock.  Only by accurate performance can accurate results be obtained.  Work not done precisely is only wasted effort.

3. ACCURATE RECORD KEEPING is one of the most important phases of your work.  It is imperative that records be made AT THE TIME of observation in a lab book and adhere to the following rules:

          A. If you make an error in writing your data, NEVER ERASE!   NEVER USE WHITE OUT!!  Merely cross out the mistake by placing a firm line through it.  It is possible to lose valuable data when you erase.

          B. Keep your data neat and well organized.  Graphs and tables do this well, so use them whenever possible.

          C. Always write in clear and simple language using words as precisely as you can.  Avoid ambiguity: this 
               means, avoid vague language and double meanings.  Words like "small" and "large" mean different
               things to different people, so it is important to be clear about what you mean.

4. MEASURING AND RECORDING MEASUREMENTS.
          A. When you express data quantitatively, do so as precisely as possible, using the Metric System.  The
               precision you have will be determined by the equipment you use.

          B. Do not indicate greater precision than you have obtained.  To state that something
               weighted 1.002 grams when your balance weighs no more precisely than 1.0 grams is unscientific. 
               If your ruler is divided into 1 mm divisions, then your precision will be tenths of mm.  So, 4.3 mm is
               fine, 4 mm is not as precise as you can be, 4.30 mm is more precise than your ruler allows you to be.
               (Don't think changing the units will change the rules! In the example given previously, you could
              record the measurement as 0.43 cm, but 0.4 cm is not precise enough, and 0.430 cm is more precise
              than you can be with this ruler.)

          C. When estimating the last digit of a measurement (such as with a ruler or graduated cylinder), follow
               these rules:
                   1. If the item falls exactly on the mark, then the last digit is "0".
                   2. If the item falls exactly halfway between the two marks, then the last digit is "5"
                   3. If the item falls between a mark and halfway to the other mark, then the last digit will be
                              "2"- if it is closer to the mark than the halfway point;  OR
                              "3"- if it is closer to the halfway point than to the mark.
                   4. If the item falls between the halfway point and the next mark, then the last digit will be
                              "7"- if it is closer to the halfway point than to the next mark;
                              "8"- if it is closer to the next mark than to the halfway point.
                   5. Notice the last digit, which is estimated, will never end in "1", "4", "6", "9" !

         D. When averaging results, round off only to the same position right or left of the decimal point as the
               LEAST PRECISE measurement taken.  To carry the average to several decimal places beyond
              those taken in measurements leads to a false impression of accuracy.  This is also unscientific.

4. Graphs of quantitative data are important in scientific communication.  Use them whenever you can.  Most of the graphs you will use in biology this year will be line graphs.  Line graphs are used when the independent variable is continuous (such as "time"); whereas bar graphs are best when the independent variable is discrete (such as "cities").  When you are graphing results in a line graph make sure you do the following:

          A. Make sure the vertical and horizontal axes are straight;
          B. Make the divisions on the axis equal (for example, there should be the same amount of space
               between 2 grams and 3 grams as between 11 grams and 12 grams);
          C. Put the dependent variable on the vertical axis (Y-axis)  and the independent variable on the
               horizontal axis (X-axis).
          D. Label the quantities precisely on the vertical and horizontal axes using the appropriate units.
          E. Plot the points accurately
          F. Connect the points (with smooth lines, if possible); do not connect the line to "0" unless this is
               an actual data point.
          G. Give the entire graph a concise title.

5. Drawings are also important parts of records.  They should be made with a pencil and continuous lines.  When making a drawing follow these guidelines:
            A. Label structures neatly and place all names horizontally on the right hand side of the drawing.
            B. Label lines running to the structures should NOT CROSS.
            C. Be sure to give the drawing a title, preferably placed below it.
            D. Drawings of items viewed with a microscope MUST include the total magnification used.