"5657","Research on Problem Difficulty (in Chinese)","This paper examines some sources of problem difficulty with the tool of a new type of artificial problems. The sources are: 1) the number of known variables: it has no effects on problem difficulty. 2) the number of unknown variables: problem difficulty will increase when it  increases. 3) whether prompting the names are not prompted. 4) the arrangement of variables; problem difficulty will increase if variables are arranged in disorder. 5) the number of operations (processes) to choose; problem difficulty will increase when it increases. 6) the similarity of the operations to choose: problem difficulty will increase when operations are similar. 7) the style of presentation of the former problems; it can change the likelihood that the attributes of problems enter man’s sphere of consciousness; problem difficulty will increase when the attributes of the former problems are unlikely to enter man’s sphere of consciousness.","http://cogprints.org/5657/","Shao, Z. F. and Liu, Y. F. and Zhong, Y. P.","UNSPECIFIED","       <span class=\"person_name\">Shao, Z. F.</span> and <span class=\"person_name\">Liu, Y. F.</span> and <span class=\"person_name\">Zhong, Y. P.</span>     (1996)  <a href=\"http://cogprints.org/5657/\"><em>Research on Problem Difficulty (in Chinese).</em></a>       [Journal (Paginated)]           ","","1996"