Stratified Random Basis Research Articles

Efficacy of a topical formulation of eprinomectin against endoparasites of cattle in New Zealand

Two controlled studies involving 24 cattle were conducted in New Zealand to determine the efficacy of a topical, non-flammable formulation of eprinomectin against induced and naturally acquired nematode infections. In Trial 1, nematode infections were induced on Day -5 with third-stage larvae of Cooperia spp., Haemonchus contortus, Ostertagia ostertagi and Trichostrongylus colubriformis so that the nematodes would be at the fourth larval stage when the cattle were treated. In Trial 2, cattle had naturally acquired nematode infections as determined by faecal nematode egg counts and larval cultures. The cattle were allocated on Day 0 (Trial 1) or Day -6 (Trial 2) on a stratified random basis according to bodyweight to one of two treatments: untreated control or eprinomectin (0.5% w/v) applied topically at 1 ml/l0 kg bodyweight. Necropsies were undertaken on Days 14 and 15 and total nematode counts were done. In Trial 1, cattle treated with eprinomectin had significantly (p < 0.05) fewer Cooperia spp. and O. ostertagi than the controls. Larvae of H. contortus and T. colubriformis did not establish. In Trial 2, cattle treated with eprinomectin had significantly (p < 0.05) fewer of the following parasites than the controls: Haemonchus spp. (adult), Cooperia surnabada (adult), C. oncophora (adult), Cooperia spp. (L4), Ostertagia lyrata (adult), O. ostertagi (adult), Oesophagostomum spp. (adult), T. axei (adult and L4) and Trichuris spp. (adult). Reductions of 100% were observed for Capillaria spp. (adult), D. viviparus (adult and L4), and Nematodirus helvetianus (adult), but these were not statistically significant (p > 0.05) because four or fewer control animals were infected with these parasites. In Trial 2, efficacies of greater than 99% were observed against all species for which moderate to high burdens occurred in the untreated controls. These findings indicate that eprinomectin in a topical formulation is a highly effective nematocide in cattle.

The Character of Learning Disabilities: An Iowa Profile

This article summarizes the findings from The Iowa Learning Disabilities Evaluation Project, designed to study the nature and characteristics of students with learning disabilities (LD) in the state. A sample of 917 LD students was selected on a stratified random basis from Iowa Area Education Agencies (AEA). Data were collected from a survey completed by AEA personnel for each LD student selected focusing on pupil characteristics as well as information related to assessments, programs, and services. The outcome was a comprehensive description and profile of LD students in the state of Iowa.

Controversy versus concurrence seeking in multi‐grade and single‐grade learning groups

AbstractThe effects of controversy and concurrence seeking and participation is age‐homogeneous and age‐heterogeneous cooperative learning groups were compared on achievement, achievement motivation, perspective‐taking accuracy, and interpersonal attraction. In addition, the interaction among students within the cooperative learning groups was observed. One‐hundred‐twelve 4th‐, 5th‐, and 6th‐grade students were assigned to conditions on a stratified random basis controlling for age, sex, reading ability, and homerooms. In all conditions, students studied two controversial issues with materials representing both pro and con views. In the controversy condition each small group was divided into two halves representing the pro and con sides. In the concurrence‐seeking condition each small group studied pro and con materials on alternating days and were told to learn the material without arguing or disagreeing with one another. In the multi‐age conditions 4th‐, 5th, and 6th‐graders were placed in the same learning groups, while in the single‐age conditions students were placed in small groups with peers of the same age. The results indicate that controversy promoted higher achievement, greater achievement motivation, and more accurate perspective taking than did concurrence seeking. Multi‐age learning groups had greater achievement motivation than did the single‐age groups.

Oral Interaction in Cooperative Learning Groups: Speaking, Listening, and the Nature of Statements Made by High-, Medium-, and Low-Achieving Students

Abstract Oral interaction within cooperative learning groups was observed for high-, medium-, and low-achieving students. Initially, cooperative and individualistic learning situations were compared on achievement and attitudes. Forty-eight 4th-grade American students were assigned to learning situations on a stratified random basis controlling for ability and sex. They participated in the study for 55 min a day for 15 instructional days. Two observation schemes were used. The results for the cooperative situation were factor analyzed to determine the basic dimensions of oral interaction within cooperative learning groups. Five orthogonal factors were identified: Exchanging Task-Related Information, Elaborating on the Information, Encouraging Each Other to Learn, Disagreeing with Each Other's Conclusions, and Making Nontask Comments and Sharing Personal Feelings. The oral participation of students from different achievement levels was differentially related to achievement. Vocalizing was found to be more strongly related to achievement than was listening to other group members vocalize. Medium and low achievers especially benefited from cooperative learning experiences.

The effect of cooperative and individualistic learning experiences on positive and negative cross-handicap relationships

The effects of cooperative and individualistic learning contingencies on interpersonal attraction, social acceptability, and self-esteem between handicapped and nonhandicapped fourth-grade students were tracked and compared. Sixty-nine students were assigned to conditions on a stratified random basis controlling for handicap, sex, and age. They participated in the study for 45 min a day for 54 instructional days during science class. Nonhandicapped peer ratings of the social acceptability of each handicapped student and several attitude measures were obtained four separate times at 18-day intervals. The results indicate that continued use of cooperative learning contingencies promote positive growth in interpersonal attraction, social acceptability, and self-esteem between handicapped and nonhandicapped students. The results also indicate that when cooperative learning contingencies are replaced with individualized learning contingencies, decay in the above-mentioned variables occurs.

Effects of single‐sex and mixed‐sex cooperative interaction on science achievement and attitudes and cross‐handicap and cross‐sex relationships

AbstractSingle‐sex cooperative, mixed‐sex cooperative, and individualistic learning situations were compared to determine if they promoted systematic differences in relationships between male and female students and handicapped and nonhandicapped students. One‐hundred‐fifty‐four 5th‐and 6th‐grade students were assigned to conditions on a stratified random basis controlling for ability, sex, grade level, homerooms, and handicap. They participated in a study for 45 minutes a day for 21 days in science class. The results indicate that cooperative learning situations, compared with individualistic ones, promoted more positive cross‐sex and cross‐handicap relationships. Males achieved higher and had more positive attitudes toward science than did females.

The effects of controversy, concurrence seeking, and individualistic learning on achievement and attitude change

AbstractThe effects of cooperative‐controversy, cooperative‐concurrence seeking, and individualistic learning were compared on motivation, achievement, and attitudes toward the science subject being studied. Eighty‐four fifth‐grade students were assigned to conditions on a stratified random basis controlling for sex and reading ability. In all three conditions students studied whether wolves should or should not be a protected species. The results indicate that cooperative‐controversy resulted in the highest achievement, greatest motivation to learn more about wolves, more positive attitudes toward the wolf, and more positive attitudes toward controversy.

Classroom Conflict: Controversy Versus Debate in Learning Groups

The effects of two types of structured academic conflict, controversy and debate, were compared with individual study on a number of dependent variables. Seventy-two sixth grade students were assigned to conditions on a stratified random basis controlling for sex, reading ability, and handicapping conditions. In all three conditions students studied a controversial issue with materials representing both pro and con views. In the controversy condition each learning group was divided into two pairs representing the pro and con sides. In the debate condition each member of a learning group was assigned a pro or con position to represent in a debate with the other three members. In the individualistic condition subjects were told to learn the material without interacting with other students, and each student was given all the pro and con materials. The results indicate that controversy promotes the most verbal rehearsal and exchange of the assigned material, the most concern that all students master the assigned material, the most active search for more information about the topic being studied, the most reevaluation of one’s position and the most attitude change, the most liking for the subject matter and the instructional experience, the highest self-esteem, and the most accepting and supportive relationships among handicapped and nonhandicapped students. The debate condition generated higher levels of these dependent variables than did individualistic study.

Cross-Ethnic Relationships: The Impact of Intergroup Cooperation and Inter group Competition

Intergroup cooperation and intergroup competition were compared to determine if they promoted systematic differences in interaction between majority and minority students. Fifty-one fourth-grade students were assigned to conditions on a stratified random basis controlling for minority status and sex. They participated in a study for 55 minutes a day for 10 instructional days. The results indicate that intergroup cooperation promoted more inclusion of minority students and more cross-ethnic relationships.

The effects of intergroup cooperation and intergroup competition on ingroup and outgroup cross-handicap relationships.

Abstract Intergroup cooperation and intergroup competition were compared to determine whether they promoted systematic differences in interaction patterns and interpersonal attraction between high- and low-status students. Fifty-one fourth-grade students were assigned to conditions on a stratified random basis with handicap status and sex controlled. They participated in a study for 55 minutes a day for 10 instructional days. The results indicate that intergroup cooperation promoted more inclusion of handicapped students and more cross-handicap relationships.

Structuring academic conflicts between majority and minority students: Hindrance or help to integration

The effects of two types of structured academic conflict, controversy and debate, were compared with individual study in a study on desegregation. Seventy-two sixth grade students were assigned to conditions on a stratified random basis controlling for sex, reading ability, and ethnic membership. In all three conditions students studied a controversial issue with materials representing both pro and con views. In the controversy condition each learning group was divided into two pairs representing the pro and con sides. In the debate condition each member of a learning group was assigned a pro or con position to represent in a debate with the other three members. In the individualistic condition subjects were told to learn the material without interacting with other students and each student was given all the pro and con materials. The results indicate that controversy promotes the most cross-ethnic verbal rehearsal and exchange of the assigned material, the most concern that all students master the assigned material, the most active search for more information about the topic being studied, the most reevaluation of one's position and incorporation of opponents' arguments, the most liking for the subject matter and the instructional experience, the highest self-esteem, and the most accepting and supportive relationships among minority and majority students. The debate condition generated higher levels of these dependent variables than did individualistic study.

Are low achievers disliked in a cooperative situation? A test of rival theories in a mixed ethnic situation

The effect of cooperative and individualistic learning experiences within which majority students worked with lower-achieving minority peers were compared. A number of theories predict that when white students collaborate with lower-achieving minority students prejudice and rejection will increase. These theories were tested against a counter position that working collaboratively promotes liking regardless of differences in achievement. Forty-eight students (20 minority and 28 white) were assigned to conditions on a stratified random basis controlling for ethnic membership, sex, social class, and ability level. They participated in the study for 55 min a day for 15 instructional days. The results indicate that cooperative learning experiences, compared with individualistic ones, promoted higher achievement for minority students, more cross-ethnic interaction aimed at supporting and regulating efforts to learn and ensuring the active involvement of all students, and greater cross-ethnic interpersonal attraction. The results do not support the theories that posit equal achievement levels are necessary for successful integration and do support the position that cooperative experiences result in liking regardless of the ethnic membership or achievement level of collaborators.

Effects of cooperative, competitive, and individualistic learning experiences on social development.

A comparison was made of the effects of cooperative, competitive, and individualistic learning experiences on relationships between handicapped and nonhandicapped students and their self-esteem and perspective-taking ability. Fifty-nine students were assigned to conditions on a stratified random basis controlling for handicap, ability, and sex. Students participated in two instructional units for 60 minutes a day for 15 instructional days. Behavioral measures were taken for cross-handicap interaction during instruction and during daily free-time periods. The results indicate that cooperative learning experiences, compared with competitive and individualistic ones, promote more interpersonal attraction between handicapped and nonhandicapped students and promote higher self-esteem on the part of all students. Cooperation promoted greater perspective-taking ability than did competition.

The effects of cooperative and individualistic instruction on handicapped and nonhandicapped students.

Summary Comparisons were made of the effects of cooperative and individualistic learning experiences on interpersonal attraction between handicapped and nonhandicapped eleventh-grade students and their achievement. Thirty-one students were assigned to conditions on a stratified random basis, with control held for handicap, ability, and sex. They participated in one instructional unit for 55 minutes a day for 16 instructional days. A behavioral measure was employed for cross-handicapped interaction within the instructional situation. A number of attitude and achievement measures were also given. The results indicate that cooperative learning experiences, compared with individualistic ones, promote more cross-handicapped interaction during instruction, more interpersonal attraction between handicapped and nonhandicapped students, and higher achievement on the part of both handicapped and nonhandicapped students.

Effects of Cooperative, Competitive, and Individualistic Learning Experiences on Cross-Ethnic Interaction and Friendships

Summary The effects of cooperative, competitive, and individualistic learning experiences were compared on interethnic interaction and attitudes among 4th-grade boys and girls. Seventy-six students were assigned to conditions on a stratified random basis controlling for ethnic membership, ability, and sex. They participated in two instructional units for 45 minutes a day for 15 instructional days. Behavioral and attitudinal measures were taken for cross-ethnic interaction during the instructional sessions and during daily free-time periods. The results indicate that cooperative learning experiences, compared with competitive and individualistic ones, promoted more cross-ethnic interaction and more positive cross-ethnic attitudes.

Effects of cooperative and competitive learning experiences on interpersonal attraction between handicapped and nonhandicapped students.

Summary The effects of cooperative and competitive learning experiences on interpersonal attraction between handicapped and nonhandicapped, fourth-grade students were compared. Fifty-one students were assigned to conditions on a stratified random basis controlling for handicap, ability, and sex. They participated in two instructional units for 45 minutes a day for 15 instructional days. Cross-handicap interaction during daily free-time periods and a number of attitudes were measured. The results indicate that cooperative learning experiences, compared with competitive ones, promote more interpersonal attraction between handicapped and nonhandicapped students.

Effects of cooperative and individualistic instruction on the achievement of handicapped, regular, and gifted students.

Summary The effects of cooperative and individualistic learning experiences were compared on achievement of academically handicapped, normal-progress, and gifted sixth-grade students. Fifty-five students were assigned to conditions on a stratified random basis controlling for ability and sex. They participated in one instructional unit for 65 minutes a day for five instructional days. The results indicate that cooperative learning experiences promoted higher achievement, greater retention, more positive attitudes among students, and higher self-esteem than did individualistic learning experiences.

Building Friendships Between Handicapped and Nonhandicapped Students: Effects of Cooperative and Individualistic Instruction

The effects of cooperative and individualistic learning experiences were compared on interpersonal attraction between handicapped and non-handicapped third-grade students. Forty students were assigned to conditions on a stratified random basis controlling for handicap, ability, sex, and peer popularity. Students participated in an instructional math unit for 25 minutes a day for 16 instructional days. Type of interaction within the instructional situation, interpersonal attraction, and frequency of interaction in a free-choice, postinstructional situation were measured. Three attitude scales were also given. The results indicate that cooperative learning experiences, compared with individualistic ones, promote more cross-handicapped interaction during instruction; promote interaction characterized by involving handicapped students in the learning activities, giving them assistance, and encouraging them to achieve; promote more cross-handicap friendships; and promote more cross-handicap interaction during postinstructional free-time.

Effects of Controversy on Epistemic Curiosity, Achievement, and Attitudes

Summary Comparisons were made of the effects of controversy versus no-controversy on epistemic curiosity, achievement, and attitudes of fifth- and sixth-grade Ss. Eighty Ss were assigned to conditions on a stratified random basis, with control held for class membership, reading ability, and sex. Within each condition they were assigned to groups of four on a similar stratified random basis so that there were an equal number of fifth- and sixth-grade groups, each one made up of a boy and a girl of high-reading-ability and a boy and a girl of low-reading-ability. Ss participated in two five-day instructional units, half participating in structured argumentation with their fellow group members and half discussing the material without arguing with their peers. Behavioral measures were taken on Ss' epistemic curiosity. The results indicate that controversy, compared with no-controversy, leads to more epistemic curiosity, higher achievement, and more positive attitudes.

The integration of the handicapped into the regular classroom: Effects of cooperative and individualistic instruction

The effects of cooperative and individualistic learning experiences on interpersonal attraction between handicapped and nonhandicapped fourth-grade students were compared. Fifty-one students were assigned to conditions on a stratified random basis controlling for handicap, ability, and sex. Students participated in one instructional unit for 45 min a day for 16 instructional days. Behavioral measures were taken for cross-handicapped interaction within the instructional situation, during daily free-time periods, and during a postexperimental problem-solving situation with new peers. A number of attitude measures were also given. The results indicate that cooperative learning experiences, compared with individualistic ones, promote more cross-handicapped interaction during both instructional and free-time situations and more interpersonal attraction between handicapped and nonhandicapped students.