Research Summary No.  70 
                            Development of Intrinsic Motivation Scale 
                                                         By 
                               Assist. Prof. Dr. Oraphin  Choochom 
                                            Assist. Prof. Ashara Sucaromana 
                                            Dr. Willadlak Chuawanlee 


                    The purposes of this study were (1) to  construct and develop valid and reliable  intrinsic motivation
scale, (2)  to analyze factors of intrinsic motivation, (3)  to compare gender  and age differences in intrinsic motivation,
and (4) to establish norms of intrinsic  motivation scale. 
                    The  sample consisted of 573  teachers, 685  7 th  (M.S.1)  432  9th (M.S. 3) grade students , and  510
upper secondary students  (M.S. 5  and M.S. 6)  from secondary schools under the Department of General Education,
Ministry of Education in the Bangkok Metropolis in 1997-1998 academic year. 
                     The major instrument was intrinsic motivation scale (student form and adult  form). Both student and adult
forms were identical in contents, yet there were some little contextual differences. The intrinsic motivation scale
contained  45  items for full version and 30 items for full version and 30  items for short version on a five-point scale,
from 1= never true of me to 5 = always true of me. Besides, there were other measures of similar and different constructs
from the intrinsic motivation scale used in order to examine the construct validity of intrinsic motivation scale.  These
measures were acceptable in validity and reliability. Questionnaires and inventories were administrated for collecting data.
The program SPSS  was used to analyze descriptive statistics, reliability coefficients, t-test, correlations, factor analysis,
analysis of variance, and multivariate analysis of variance. The program  AMOS was also employed to conduct
confirmatory factor analysis. 
                   The findings were summarized as follows : 
                     1.  Intrinsic motivation scale had ability to differentiate high and low scorers on this scale. The items had
adequate to high discriminating powers. The homogeneous set of items were also found. 
                     2.  the intrinsic motivation scale should consist of  5  dimension or factors. These five factors accounted for 
33.14  and   42.81  percent of the total variance in intrinsic motivation for student and adult samples, respectively. 
                    3.  The five factor model (challenging, interest-enjoyment, autonomy, need of competence. and
determination)  fitted empirical data at acceptable levels for students and adults. The results showed that the intrinsic
motivation scale was construct with its theoretical framework indicating the construct validity. 
                    4.  The intrinsic motivation scale was positively correlated  with Picture Motivation scale, internal locus of
control, self-esteem, creativity, and thinking personality. In fact, the positive correlations  among related constructs
support convergent validity of intrinsic motivation scale. The intrinsic motivation scale was negatively correlates with
depression and anxiety. The correlations among introvert-extrovert personality, sense- perceiving personality, and
intrinsic motivation were not found, suggesting that there was discriminant validity of the intrinsic motivation scale.
Moreover, the inteinsic motivation scale was unbiased because it was independent from  social desirability. 
                    5.  The internal consistency reliability  of the intrinsic motivation scale showed Cronbach' s alpha of  .83  for
the student form and  .93  for the adult form, the test- retest reliability  ( 5  week period) of intrinsic motivation scale
reflecting stability of measurement over time was  .76  for the student form and  .71  for the adult form. 
                    6.  There were gender an age differences in intrinsic motivation. Specifically, female students student  scored
higher on global intrinsic motivation, need of competence, and determination them male students at  .01  significance
level. The results also showed that global intrinsic motivation challenging, autonomy, and determination increased from
lower secondary levels (M.S. 1 M.S. 3)  to upper secondary levels (M.S.5 ,M.S. 6). Similarly, middle-age adults (ages 
41-49) scored higher on determination than younger adults (ages below  41) 
                    7.  Percentile norms, Z-score norms, and T-score norms were available for the intrinsic motivation scale. Sex
norms and grade norms for the intrinsic motivation scale  were also provided. The possible score range on the instrument
was  45 to 225, with a middle score of 161  for the student  sample (standard deviation = 16.03) and  176  for the adult 
sample (standard deviation =  18.96). Global intrinsic motivation scores  for both samples were approximately normally
distributed. 
                    Recommendations based on the findings are summarized as follows : 
                   1.  The intrinsic motivation scale consists of  45  items for full version and  30  items for short version
assessing five dimensions of intrinsic motivation. Both versions have student and adult forms which have similar
psychometric properties.  The user should select an appropriate form or version for his/her own study. 
                    2.  Future research should be replicated, modified and further validated the intrinsic motivation scale so as to
strengthen its psychometric properties scale and lead to an even more accurate instrument. 
                    3.  In order to obtain evidence of construct validity and gain understanding of individual motivation, the
antecedents and consequences of intrinsic motivation should be examined in terms of experimental research and structural
model. 


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