Examining the effect size of the psychoeducation in a Turkish sample: a meta analysis study Mehmet Beyazsaclı 1 • Eser Gemikonaklı 1 • Mehmet Altinay 1 • Gokmen Dagli 2 Ó Springer Science+Business Media B.V. 2017 Abstract The purpose of this study is to examine the effect size of the psychoeducation in a Turkish sample. Target population is comprised by a Turkish sample. In sample selec- tion, the criterion sampling method is used. As criteria; the arithmetic mean, standart deviation and sample amount, which belong to the published experimental theses and articles have been taken as basis. The data have been examined through the method of Meta-analysis. In the study, from among the moderator variables of psychoeducation general effect size, the effect sizes and trail test size on children, adolescents, young adults and adults have been examined. General effect size of the psychoeducation has been found to be at very high level and in the favor of the experimental group. The effect sizes on emotion, idea and behavior, have been found at high, very high and at perfect levels. The effect size on adolescents and young adults has been found very high, and on adults and children, at medium level. The general effect size on the moderator variables has been found at high level. The general effect size; on children, depending upon their development periods, has been found at medium level, on adolescents and young adults at very high level. The effect size on permanence, on the other hand, has been found at high level. In conclusion, the effect size of the psychoeducation practices has been discussed within the frame of the literature and proposals have been made to educators. Keywords Anger Á Aggression Á Anxiety Á Empathy Á Emotion & Mehmet Beyazsaclı beyazsacli34@gmail.com Eser Gemikonaklı eser.gemikonakli@kyrenia.edu.tr Mehmet Altinay mehmet.altinay@neu.edu.tr Gokmen Dagli gokmen.dagli@neu.edu.tr 1 University of Kyrenia, Kyrenia, Cyprus 2 Near East University, Faculty of Education, University of Kyrenia, Nicosia, Cyprus 123 Qual Quant DOI 10.1007/s11135-017-0620-6