The impact of using problem-solving puzzles on Iranian intermediate EFL learners' lexical knowledge

This study tried to investigate the impact of using problem-solving puzzles onIranian Intermediate EFL learners' lexical knowledge. At first a homogenoussample of 30 Intermediate EFL learners attending in the third grade of Shahedhigh school in Lahijan were selected and they were randomly divided into twogroups, as experimental group and control group. In the first session, the pretestwas administrated to determine the significant differences between the two groupsand revealed they were homogenous. The scores were kept being compared withthe second set of scores in posttests. The control group received traditional andregular procedure. The experimental group was exposed with some different kindsof puzzles with some special training by using new techniques to learnL2vocabulary more effectively. The treatment lasted 10 sessions. At the end, thedata was analyzed via calculating an Independent Samples T-test between post testscores of the experimental and the control group. The result of the test showed thatthe experimental group did not show a subtle improvement in lexical knowledgeafter the instruction.The students had fun but the analysis is proved that the nullhypothesis was supported in this study because of the same results of both groups.