Grade Level: 6th - 8th; Type: Physics
Determine how good we are at direct and indirect observation.
- What is the Scientific Method?
- What is a hypothesis?
- Define direct observation.
- Define indirect observation?
- Which type of observation, direct or indirect would yield more reliable results?
- What is meant by reliability in scientific research?
- What is meant by validity in scientific research?
On the skills level, this experiment serves to acquaint students with the basic processes of observation, namely, direct and indirect observation in determining the properties of a various objects and substances. Direct observation is operationally defined as an observation made by using your senses as opposed to indirect observation made by using instruments and measuring devices. Essentially all of sciencing depends on the quality of the processing skills which students use in thegathering of essential data in conducting their experiments. The more accurate the observations, the more accurate the results. The more accurate the measurements, the more precise and correct are the results.
This science fair experiment also serves to acquaint students with the process of putting together a science fair project, clearly delineating an objective, stating his or her own hypothesis as to the anticipated outcome and at times justifying the hypothesis based on previous research. In addition, the student learns to follow directions, record observations, employ a variety of data collection vehicles such as use of charts, graphs and photos. Finally, the student organizes a bibliography of all the various resources used in obtaining the vital data. The entire project serves as an excellent experience in training the mind to organize and process data in a systematic, organized way for a very specific purpose.
- Small solid wooden objects (such as rectangular blocks and balls)
- Magnifying glass
- Metric ruler
- Magnifying glass
- Red vegetable coloring
- 3 jars of various sizes or 3 soda bottles of different sizes
- Rod for stirring
These materials may be borrowed from the school laboratory or purchased from Science Kit or FisherScientific Co.
- Gather all the materials which you will need for this project.
- Copy the chart provided below so that you nay readily record your observations.
- Formulate your hypothesis as to the effectiveness of direct versus indirect observation in obtaining data that is most accurate and provide your rationale for your response.
- Examine each of the wooden objects using your senses. In your data table, make a list of the properties you observed. Do not test for the taste property!
- Observe each of the wooden objects with a magnifying glass. Record your observations in the chart.
- Use a balance to determine the mass of each of the wooden objects. Add the mass to your list of properties.
- Use your metric ruler and measure the length, width, height and diameter (where applicable) of each of the wooden objects and record the data.
- Make a red solution of water and vegetable coloring. Take the three bottle or jars of different sizes and fill them about half full of the red solution. Label them A, B, and C.
- Just using your eyes estimate the volume of colored liquid are in each of the three containers and record your data.
- Now, using the graduated cylinder measure the amount of red solution in each of the three containers and record your data in the chart.
- Review your hypothesis. . Check your data chart. In what way do instruments affect your data and impact on your power of observation?
- Write up your experiment. Include your data chart. You may wish to take photos of the various steps of this experiment. Be certain to include your bibliography.
- You may wish to go further and cite a variety of other instruments and procedures that we use to insure that our observations, be they direct or indirect, provide us with data that we can view as accurate and reliable. How, in our day to day living, do we employ instrumentation to insure the most accurate measurement that is possible?
Objects & Materials
red solution A
red solution B
Red solution C
Terms/Concepts: The Scientific Method; Hypothesis; Direct observation; Indirect observation; Reliability; Validity
- Gardner, Robert. Kitchen Chemistry; Science Experiments to Do at Home. New York, Messner,1982