Developing Expertise for
Welcome! This page provides perspectives, general practices and links to resources for helping students to develop expertise for conducting studies in science & technology. Correlational studies can be used for Judging Ideas, which is a major phase of my constructivism-informed pedagogical framework. If you have comments, questions, suggestions, resource ideas, etc. about anything here, please write to me about them. Thanks.
scientists & technologists seek empirical support for claims about
phenomena, they often use studies. A study is an approach that should
be distinguished from 'experiments,' about
which perspectives and practices are provided elsewhere. As indicated in the
figure here, a study
involves collecting data regarding variables that change naturally. To develop ideas about
food decay, for example, we could
some food-bacteria mixtures in nature, measure their temperatures and
determine the rate of decay in each case. This particular inquiry
would be a correlational
investigators would be comparing (correlating) how changes in one
variable (e.g., natural temperature changes) may affect changes in
another variable (e.g., rate of decay). Again, studies should be
contrasted with experiments, which involve forcing changes to occur in
a possible 'cause' (independent) variable. In the figure here, a
decay experiment would involve steadily increasing the temperature (an
independent variable) at which
food-bacteria mixtures are kept and measuring the rate of decay of the
food (a dependent ['result'] variable).
Which of these two sorts of investigations inquirers choose to use depends on various factors. Experiments often produce quick results and, for that reason, they may be preferred over studies. Sometimes, however, experimentation is impractical and, therefore, studies are necessary — as in the case of much of astronomical studies, for example. Perhaps more significantly, it often is ethically problematic to conduct experiments in some cases. With every experiment, there is a risk of negative side-effects of forcing a variable to change. Of the numerous examples, asking volunteers to smoke different numbers of cigarettes in order to deterine cigarettes' effects on human heart rate may work, but it risks giving them lung cancer! — along with other possible unexpected negative side-effects.
|There are various approaches for helping students to develop skills they could use for conducting correlational studies, but resources here are based on the constructivism-based approach at Skills Pedagogy. Resources for the Modelling & Practice stages of this framework are provided on this page, through the links at right. Resources for helping students to express their pre-instructional skills for science inquiry (including experimentation) are provided at Expressing Inquiry Skills.|
Teachers can engage students in Socratic
about studies, first pointing out differences between studies and
experiments — perhaps by
discussing what would be controversial studies; such as a marijuana
study of rates of human coughing (which some students may realize also
might cause cancer). More extreme inappropriate uses of studies also
could be mentioned, such as those performed by
the Nazis during the Holocaust. More benign examples also may be
used, like these. A demonstration like
that below could then be used to reinforce these ideas. During
and after such discussions, teachers should ensure students at least
begin to develop understandings of important principles relating to
example, those ideas described briefly at right.
demonstration, which can later be used for student practice, involves
use of a ruler (of varying sorts) to measure a person's reaction rate.
The "0" end of a ruler is held just above the imaginary plane from the
top of the person's thumb to the top of his/her forefinger, as
indicated at right. The person should hold his/her thumb and forefinger
at a particular distance (e.g.,
the width of the ruler). The person holding the ruler should pretend to
drop the ruler a few times to ensure the subject (person
attempting to catch the ruler) does not react too quickly and unfairly.
The person holding the ruler should drop it without indicating it is
going to be dropped. Assuming the subject catches the ruler, the point
at which it is caught (e.g., at the top of the person's finger and
thumb) should be recorded. This distance measurement can be converted
into a sort of 'rate' measurement by dividing 1.0 by the number. This
produces a ratio that would increase as a person gets faster at
reacting (i.e., a short distance is taken to catch the ruler). The
person can be given three trials, perhaps, and an average calculated.
Having demonstrated how this measurement works, the teacher could ask
students to brainstorm possible causes for why people might have
different reaction rates. Some possibilities include: amount of sleep,
length of fingers, related hobbies (e.g., piano playing), sex (male vs
female), age, distance between the eyes, etc., etc. A series of
students may volunteer to be studied during the demonstration, but this
study likely is best conducted as a whole class practice activity — as
below. In discussions about possible cause variables that could affect
reaction time, you could get students to consider variables like
cigarette-smoking and alcohol consumption - as connections to WISE Problems.
several other demonstrations involving observations about
students that teachers can use for providing instruction in the nature
of studies. Some other variables that could be measured and then
correlated with other variables are: i) various body dimensions (e.g.,
arm length and leg length, heart rate and body weight, etc.).
Again, in conducting these demonstrations, teachers should be careful to ensure students understand points like those above about studies.
Reading: Teachers should encourage students to
sources of information about the nature of studies and, especially,
correlational studies. Some reading of this sort is provided with some
of the practice activities available below.
Information also is available on various Web site, such as at Correlational
Research and through Skills Ed. Resources.
|Students should be given several opportunities to gain some practice in developing expertise regarding studies. Generally, these may involve: i) designing & conducting studies and/or ii) analyzing & evaluating completed inquiries. As students work through the various activities, they should have opportunities to interact with peers. Teachers also should interact with students on a regular basis, questioning them about what they are doing and reasons for their actions. Generally, teacher interactions should encourage students to develop independent experitse, rather than developing a reliance on the teacher for the 'right' answers, methods, etc. Some specific suggestions for these sorts of activities are provided at right, along with links to relevant resources.||