In a controlled experiment, presenting words in a small font leads to better memory recall than presenting words in larger font. when teachers adopt small font for class reading materials, however, there is no improvement in students’ recall. what does this study lack?

That a small font leads to better memory recall than presenting words in a larger font,it is only the scientific fact which is external validity.Students who are studying with concentration only able to recall the words in memory it not matters with any small or larger words. The words which are described with pictures can easily recall by students.So there will huge improvement in studies among students.

Americans often speak of their country as one of several large regions.  these regions are cultural units rather than governmental units --  formed by history and geography and shaped by the economics, literature and folkways that all the parts of a region share. what makes one region different from another? a region's multicultural heritage as well as distinct demographic characteristics like age and occupation make regions different and special. within several regions, language is used differently and there are strong dialects. there are also differences in outlook and attitude based on geography.