This report presents the results of the largest survey and testing program for students in home schools to date. In Spring 1998, 20,760 K-12 home school students in 11,930 families were administered either the Iowa Tests of Basic Skills (ITBS) or the Tests of Achievement and Proficiency (TAP), depending on their current grade. The parents responded to a questionnaire requesting background and demographic information. Major findings include: the achievement test scores of this group of home school students are exceptionally high--the median scores were typically in the 70th to 80th percentile; 25% of home school students are enrolled one or more grades above their age-level public and private school peers; this group of home school parents has more formal education than parents in the general population; the median income for home school families is significantly higher than that of all families with children in the United States; and almost all home school students are in married couple families. Because this was not a controlled experiment, the study does not demonstrate that home schooling is superior to public or private schools and the results must be interpreted with caution. The report clearly suggests, however, that home school students do quite well in that educational environment.

          By current estimates, there are between 700,000 and 1,200,000 students enrolled in home schools in the United States. Further, by all accounts, the movement has been growing steadily over the past few years (Lines, 1998). Yet, there is very little scientific literature concerning the population of home school students or even large samples of home school students.
          This study describes the academic achievement levels and some basic demographic characteristics of a large sample of students and their families. While the academic levels of home school students are described in terms of public and private school norms, this study is not a comparison of home schools with public or private schools. Such comparisons would be fraught with problems. Home schooling is typically one-on-one. Public schools typically have classes with 25 to 30 students and an extremely wide range of abilities and backgrounds. Home school parents are, by definition, heavily involved in their children's education; the same, unfortunately, is not true of all public or private school parents. Home schools can easily pace and adapt their curriculum; public and private schools typically have a mandated scope and sequence. The list of differences could continue.
          This study seeks to answer a much more modest set of questions: Does home schooling tend to work for those who chose to make such a commitment? That is, are the achievement levels of home school students comparable to those of public school students? Who is engaged in home schooling? That is, how does the home school population differ from the general United States population?

Methods

Iowa Tests of Basic Skills (ITBS)

Tests of Achievement and Proficiency (TAP)

Background Questionnaires

Bob Jones University Press Testing and Evaluation Service

Data Generation Procedures

1. Parents contracted with Bob Jones University to be administered the Iowa Tests of Basic Skills or the Tests of Achievement Proficiency (39,607 students in probably 22,000 families).
2. Bob Jones certified test administrators, many of whom were the students' parents.
3. BJU sent questionnaires and answer forms to the test administrators.
4. Tests and questionnaires were returned to BJU. BJU bundled the tests and sent them to Riverside Publishers for machine scoring. BJU bundled the questionnaires and sent them to National Computer Systems for scanning. Unlike in previous studies, the parents did not know their scores ahead of time.
5. Electronic copy of the 23,415 test results and 23,311 questionnaire results were sent to the author of this report. These sets were merged to provide 20,900 cases with matching identification numbers. In order to weight by state public school enrollment, 140 cases with missing state data were dropped. A total of 20,760 students formed the initial dataset used in the study. After we formed the dataset with 20,760 students, we asked for the remainder of the 39,607 achievement test scores. We were informed that it would not be possible to disaggregate the remaining home school students from students in private schools also contracting testing services.

Characteristics of Home School Students and Families

          As shown in Table 2.1, respondents came from each of the fifty states. Several states, including Ohio, Georgia, and Virginia, have exceptionally high representation given their size. This is probably due to the fact that these states require testing of home school students. To reduce the effects of these and other overrepresented states, the data were weighted in all subsequent analyses by the number of public school students in each state. While we would have preferred to weight by the number of home schooled students in each state, such data are not available for all 50 states (Lines, 1998).

Student Age and Gender

          Table 2.2 shows the distribution of the respondents by gender and age. About 50.4% or 10,471 of the respondents were females; 49.6% (10,319) were males. These figures are comparable to that of the population of 3 to 34 years old enrolled in school (see U.S. Bureau of the Census, 1998, Table A-2). Some 51.4% of school enrollees nationally are male. The percentages are comparable at all age levels.

Student Grade

          Home school student grade placement was identified by their parents, presumably based on the grade level of the instructional materials. That grade was used by BJU to determine the test levels and used in this report as a grouping variable. Tables 2.3 shows the distribution of respondents and the nation by grade. There is a large difference in the proportions of high school (grades 9-12) home school students and the nation. Compared to the national data, a relatively small percentage of home school students are enrolled in high school. Possible reasons for this lower participation for high school students may be the relative newness of the home school movement, early graduation from high school, and possibly a desire on the part of some home school parents to enroll their children in a traditional high school. The distributional differences for students in grades 1 through 8 are minor.

Student Race

          Table 2.4 shows the racial distribution of home school students in 1998 and for the students enrolled in elementary and secondary public and private schools nationally in 1994. The distributions are quite different. The vast majority of home schooled children are non-Hispanic White. The largest minority groups for home school students (not shown in the table) are American Indians and Asian students who comprise some 2.4% and 1.2% of the home school students, respectively.

          The great majority of home school students are in married couple families. In contrast, only 72% of the families with at least one child enrolled in school nationwide are in married couple families (Bruno and Curry, 1997, Table 19).

Children at Home

          Table 2.6 shows the distribution of children in home school families and families with children under 18 nationwide. On average, home school students are in larger families. Nationwide, most families with school-age children (79.6%) have only 1 or 2 children with a mean of about 1.9 children per family. Most home school families (62.1%) have 3 or more children with a mean of about 3.1 children per family.

Mother's Religion

          We asked the home school families to identify the religious preference of each student's mother by selecting from a list of 27 religions. As shown in Table 2.7, the largest percentage of mothers identified themselves as Independent Fundamental, Baptist, Independent Charismatic, Roman Catholic, Assembly of God, or Presbyterian. The religious preference of the father was the same as that of the mother 93.1% of the time.

Parent Academic Attainment

          As shown in Table 2.8, home school parents have more formal education than the general population. While slightly less than half of the general population attended or graduated from college, almost 88% of home school students have parents who continued their education after high school.

          National data on family income are available for 1995. As shown in Table 2.9, home school families span all income levels. On average, home school families have a higher income level than do families with children nationwide and all families nationwide. The median family income level for home school families in 1997 is about $52,000. The median income for families with children in 1995, nationwide, was about $36,000.

Television Viewing

          The National Assessment of Educational Progress collects information on the television viewing habits of fourth-graders. Home school fourth-graders and fourth-graders nationally differ markedly in terms of television viewing. Home school students rarely watch more than 3 hours of television per day; nearly 40% of the students nationwide watch that much television.

Computer Use

          The Condition of Education provides a tabulation of the percent of students nationwide who report using a computer by frequency of use for 4th, 8th, and 11th graders in 1996. At each grade level, the distribution of computer use in 1998 by home school students is different from that of the nation in 1996. At each of these three grade levels, much larger percentages of home school students never use a computer. At the fourth-grade level, a much larger percent of home school students use a computer every day.

Money Spent on Educational Materials

          The amount of money spent in 1997 on home school education for textbooks, lesson materials, tutoring and enrichment services, and testing ranged from less than $200 to more than $2000. As shown in Table 2.12, the median amount of money spent was about $400.

Other Demographic Characteristics

Academic Achievement

          This same DSS scale is used for all tests and levels of the ITBS and TAP. The main advantages of the DSS are that it mirrors reality well, spans all grade levels, and provides a quasi equal interval scale which has a variety of attractive statistical properties. Most importantly, DSS scores can be compared to each other and can be meaningfully averaged.
          The main disadvantage of DSS scores is that they have no built-in meaning. Reference points are needed to interpret DSS scores. "Grade level" is one possible reference point. A DSS score of 170 in reading, for example, is about equal to the typical reading score for second-grade students in public and private schools in the spring of the year. A more refined reference is the percentile score that corresponds to each DSS score. The 170 in reading, for example, corresponds to the 54th percentile of second graders. That is, this score is better than the score received by 54 percent of the second graders using the 1995 spring norms.
          The reader should note that while all tests of the ITBS/TAP have the same median DSS score at each grade level, the distributions within each subject area vary. A DSS score of 310 for a tenth grader in reading, for example, corresponds to the 87th percentile. A DSS score of 170 in mathematics for a tenth grader would place the student at the 79th percentile.
          Percentiles are always defined in terms of a grade level. This can be problematic when analyzing data for home school students. In this study, 24.5% of the home school students were one or more grades above the grade usually associated with that student's age (see Table 3.2). A strong case can be made that rather than using the percentile corresponding to the enrolled grade, as we did in this study, one should use the percentile associated with the student's nominal grade, i.e., the grade usually associated with the student's age. The argument is that a 10-year-old home school student enrolled in 5th grade should be compared to his age peers in 4th grade. The counter argument is that the percentiles already consider the fact that students are not always in their nominal grade since the standardization sample had students above and below grade level. We initially analyzed the data both ways. Rather than expose our analysis to criticism, we chose to take the more conservative route by employing the enrolled grade.
          While very meaningful, percentiles do not provide a complete picture of a student's or group's academic performance. In this study, we used grade equivalent scores as an additional reference point for interpreting DSS scores. A grade equivalent score approximates a child's development in terms of grade and month within grade. A DSS reading score of 170 can be viewed as the typical DSS score earned by students in the ninth month of the second grade or a GES score of 2.9. Just as the percentile associated with a DSS scores varies by subtest, so do the properties of GES scores vary across subjects.
          Grade Equivalent Scores are particularly useful for estimating a student's developmental status in terms of grade. But, these scores must be interpreted carefully. An GES Score of 6.3 in reading for an 9 year old in the 3rd grade, for example, clearly indicates that the third grader is doing well. This does not, however, mean that the third grader belongs in the 6th grade. It only means that the third grader can read as well as a sixth grader.
          The usual interpretation of a Grade Equivalent Score of 6.3 for a third grader is that this third grade student can read third grade material as well as a sixth grader can read third grade material, not that he or she can read sixth grade material. The DSS of the ITBS/TAP, however, is unique. The DSS scales were developed by administering the same special scaling test to students in grades K-3, another common scaling test to students in grades 3 to 9, and another to students in grades 8-12. Thus, in the scaling study, the third graders did take the same test as the sixth graders in each subject area.

  Grade Placement

          Home school students are able to progress through instructional material at the student's rate. Thus, it is easy for home school students to be enrolled one or more grades above their public and private school-age peers. To evaluate the frequency of advanced placement, we compared students' enrolled and nominal grades. The enrolled grade was identified by the parents and used to determine the ITBS/TAP level. The nominal grade is the public school grade in which the student would normally be enrolled in based on the child's month and year of birth.
          As shown in Table 3.2, almost one fourth of the home school students (24.5%) are enrolled one or more grades above their nominal grade. While comparable figures nationally do not exist, one research director in a large school district estimated that less than 5% of their students are enrolled above grade level.

          Table 3.3 shows the median scaled score (DSS score) for home school students on the Composite with Computation, Reading Total, Language, Mathematics Total with Computation, Social Studies, and Science subtest scores by grade. The corresponding percentiles shown in the table are the within grade percentile scores for the nation that correspond to the given scaled scores. For example, home school students in Grade 3 have a median composite scaled score of 207 which corresponds to the 81st percentile nationwide. The median home school student in third grade out- performs 81% of the third graders nationwide. As an additional comparison, we provide the national median for each grade in the last column. By definition this is the 50th percentile of students nationwide.

Figure 1. Academic Achievement of Home School,
Catholic/Private and the Nation's Students

 
          The grade equivalent score comparisons for home school students and the nation are shown in Figure 2. In grades one through four, the median ITBS/TAP composite scaled scores for home school students are a full grade above that of their public/private school peers. The gap starts to widen in grade five. By the time home school students reach grade 8, their median scores are almost 4 grade equivalents above their public/private school peers.

Figure 2. Home School Students Compared to the National Norm Group in Grade Equivalent Units

Years of Home Schooling

          Almost half of the respondents (47%) indicated that they have been home schooled for each grade prior to their current grade, i.e., their entire academic life. Table 3.6 shows that students who are home schooled for their entire academic life do better than students who have been home schooled for only a few years (F academic life =108.2; df=1,9750; p<.01). There is also a significant interaction between grade and years home schooled (F=7.4; df=9,9750, p< .01), indicating that the effectiveness of home schooling varies with the student's grade. The differences are most meaningful starting in Grade 6.
          [All F ratios reported here are from a two-way analysis of variance with composite scaled scores as the dependent measure, grade as a blocking variable, and one independent variable. Because the students are within families, the dataset was trimmed by randomly selecting one child from each family. Had the full dataset been used, the variance of the children within a family would have been artificially smaller than the variance of among children in the population of inference. This would have increased the risk of Type I error, showing significance when significance may not be so. To assure adequate cell sizes, the analyses were also restricted to Grades 1 through 10. A statistically significant difference only means that there is evidence of a difference in population values. The difference may be small and not meaningful. "n.s." is used to indicate not significant.]
          One reviewer questioned whether this significant difference was due to life-long home schooling or was life-long home schooling serving as a proxy for parent education or income. The correlation of life-long home schooling and whether either parent has a college degree is .12, indicating there is some, but not a great deal of overlap between these variables. The correlation with income level was .02, indicating no relationship. Thus, whether a student is home schooled his or her entire life appears to be significantly related to achievement.

[The percentiles (%ile) shown in this and the following tables are the within-grade percentiles corresponding to the mean composite scale scores, differences and ranges refer to differences in and ranges of mean composite scale scores, sd refers to standard deviation, N is the number of students within each cell.]

  Enrolled in a Full-Service Curriculum

          There is no significant difference in the mean composite scaled scores of home school students enrolled in a full-service curriculum and home school students not so enrolled. As shown in Table 3.7, the means are quite close at all grade levels (F enrollment=.24; df=1,9750; n.s.).

  Student Gender

          There are no significant differences in the achievement levels of male versus female home school students (F for gender=.01; df=1,9750; n.s.). As shown in Table 3.8, the means are virtually identical at all grade levels.