The present study was conducted to determine the effects of favorable learning conditions on students' learning outcomes when compared with conventional instruction. Three types of favorable learning condition used in this study were the separate and the combined conditions of paraphrase of advance organizer, and mastery learning. Two teachers participated in this study. Each of them taught four classes which were made use of different instructional conditions. Two independent variables were the paraphrase condition of advance organizer and the mastery learning condition. The dependent variables were two learning outcomes: cognitive achievement and affective outcomes of social studies. The major findings of this study were as follows: First, the effect size of paraphrase of advance organizer over conventional instruction on the summative test was found to be .52. The advantage for mastery learning classes over conventional classes was .68. The effect size of the combined use of these two strategies was found to be .91. This means that the average student in the most favorable learning conditions of this study was above 82% of the students in the conventional groups. This result suggests the possibility of additive effects of the two strategies on students' achievement when these strategies are used together. Second, the strongest relationship between cognitive entry behaviors and final achievement was found in the conventional groups, where the multiple correlation reached .70. The weakest relationship, on the other hand, was found under the best learning conditions of this study, where the multiple correlation was .34. In the intermediate settings, the multiple correlation was .39 for the mastery learning groups and .51 for the paraphrase of advance organizer groups. The pattern in this result shows that where better learning conditions are provided, the relationship between cognitive entry behaviors and final achievement is reduced accordingly. This reduction was statistically significant for prior achievement. But it was not statistically significant for intelligence. Third, students who learned under favorable learning conditions liked the subject they were studying more, and were more confident of their abilities in that subject. By contrast, the level of subject - related affect and academic self - concept for the conventional groups remained the same or declined. Effect sizes for these affective outcomes ranged from .26 to .67. The result of this study shows that positive changes in students' affect occurred for students taught under improved learning conditions, though not as large an effect as what they have on cognitive outcomes.