چكيده
In this study subjects were 108 adult Iranian female learners who were at Upper-intermediate level (as defined by Kish English Institute); all the subjects had passed True To Life (TTL) Intermediate achievement tests with at least 65 percent of the whole score. They aged from 18-41. The subjects were asked to take part in a TOEFL test as a test of homogeneity. Based on the results of the TOEFL test, 12 of the subjects who were not homogenous with the rest were eliminated from the study. Therefore, the number of the subjects reduced to 96. The subjects were then assigned into four classes. One of the classes was randomly selected as the control group and the other three as experimental ones and each experimental group underwent a different Cognitive Learning Strategy. The three different cognitive learning strategies used were based on the O'Mally et al. classification of cognitive learning strategies. Semantic Mapping was considered as a Grouping strategy, Analyzing the Lexical Items was considered as a Deduction strategy, and finally Using the Dictionary was considered as a Resourcing strategy. The instruments used to collect data from the subjects included: a) A TOEFL test to determine the proficiency level of the learners and to be sure of the homogeneity of the groups prior to the experiment. b) A Language Learning Strategy Inventory Questionnaire (SILL) designed by Oxford (1990), and c) Three 50- item tests of vocabulary which were developed by the researcher. The reliability of the tests was measured by KR-21 method. Regarding the validity of the scores of the tests using Pearson Product Moment Correlation, a correlation coefficient was computed between the scores of the vocabulary part of the TOEFL test and the scores of the piloted vocabulary tests made by the researcher. The tests were then used as assessment tools in the pre-test and post-test phase of the study.
Finally, the data gathered on the characteristics of the subjects under study were analyzed and an analysis of variance through the repeated measures was run to compare the mean score of the four groups (one control and three experimental groups) on the pre-test and post-tests to see how significant the trainings were. Based on the results of the study, all Cognitive Learning Strategies used in the research were effective but only two of them (Semantic Mapping Strategy and Analyzing the Lexical Items Strategy) had significant effects on learners' retention of vocabularies; Using the Dictionary strategy was effective too but it did not have significant impacts on the vocabulary retention of the subject of the present study.
