Ed602 Lesson 1

Other Information:

Like the homework, the class notes will follow a theme. For our notes we will assume that you work at Moorhead High School. A parent has complained that the BASC assessment their child took is culturally biased. You decide to set up small research project to look for cultural biases in the assessment. You are interested in comparing the results for Hispanic students at your school with national norms for the BASC and with Caucasian students at your school. You will randomly select 25 Hispanic students and 25 Caucasian students, and give each of them the student self-report survey. The students selected are in grades 9-12, each student takes the survey in the counseling office, each student gets directions that are read from a script by the school psychologist.

Notes

Statistics is one of many tools used in the process of doing research. Long before you get to the point of needing statistics, however, you need a good research question. Below are several guidelines that need to be followed when coming up with your research question.

So, "Do students get higher grades on a weekly spelling test if they practice tracing the words on sandpaper 5 times before the test?" is a measurable, quantitative research question. However, "Should I spank my child with a rolling pin when she misbehaves?" is not a good question. It asks about what ought to be, and there are ethical issues as well when you talk about hitting a child.

Our research question is, "Is the self-report survey portion of the BASC culturally biased against youth who are Hispanic?" Comparing this to the guidelines above, this is a researchable question. It is not immoral, unmeasurable, or a question of aesthetics.

Our population can be all of the high school students in our school district who are Hispanic, or all high school youth in the country who are Hispanic, depending on the generalization desires of the researcher.

Our sample is the 25 students who are actually chosen to take the survey.

Our independent variable will be the cultural background of the students. We will not technically be changing or manipulating their culture, but we are manipulating the data to separate students by cultural background.

Our dependent variable is the scores on the BASC survey. That is where we are hoping to see (or not see) a change in response to our manipulation. If there is bias in the survey, the students who are Hispanic will have significantly different scores that the students who are not.

We have a few options for a hypothesis in regards to this study. The parent who complained has the hypothesis that there will be a significant difference in scores between the youth who are Hispanic, and the youth who are not. The null hypothesis that the school lawyers are hoping for is that there will be no significant difference between the scores of the students who are Hispanic and the students who are not.

This chapter covers broadly the initial concepts and some of the terms used in statistics. Also introduced are a number of concepts that will be important in this course. Listed below are a number of the terms and their meanings, some of which are not in the book. You do not need to memorize this list, although it would be beneficial. Most of these terms will become familiar through practice.

Vocabulary

Constant - a value that does not change for the duration of a study. Gender is usually constant during a study.

Variable - Any environmental condition or event, stimulus, personal characteristic or attribute, or behavior that can take on different values at different times. For example scores on a test can change (think pretest/posttest), weight can change in response to diet or exercise, opinions can change, age can change in longitudinal studies, or teaching methods can be changed.

Data - the scores or measurements obtained by a scientist doing research. This can be test scores, survey answers, observations made, anything recorded by the scientist for later analysis

Population - the complete set of people sharing the common characteristic specified by a researcher. So, if a study is on fourth grade students, then the population is ALL the fourth grade students in the world. If a study is on freshmen at MSUM, then the population is ALL the freshmen in MSUM.

Parameter - a single number used to describe a characteristic of a population, often symbolized by a Greek letter. A parameter for 4th grade students might be that the average 4th grade student is 9 years old.

Sample - a subset of a population. A sample of our 4th grade population might be the 4th grade students in Mr. Bryantís classroom, or the 4th grade students in Moorhead schools.

Statistic - a single number used to describe data from a sample, often symbolized by a roman letter. A statistic for Moorheadís 4th grade classes is that the average age is 9.5. (Note that a statistic is just like a parameter, except for the group of people being described.)

Independent variable - The variable that is manipulated in an experiment. If we are testing the effects of high and low sugar diets on child misbehavior, then the diet is what changes for each group of students being studied. Diet is the independent variable.

Dependent variable - The variable that is measured in an experiment. If we are testing the effects of high and low sugar diets on child behavior, then we watch to see if the groups will have different levels of misbehavior once the study begins. The misbehavior of each group in response to the new diets, is the dependent variable.

Research hypothesis - the predicted relationship between an independent and a dependent variable. If we are testing the effects of high and low sugar diets on child misbehavior, then we might have as our research hypothesis, "There will be no significant difference in child misbehavior between the low sugar and high sugar groups.