Text ( visual ) : unmediated Quantitative methods / Robert L. Linn ; Qualitative methods / Frederick Ericson. -- New York : Macmillan ; London : Collier Macmillan , c1990. -- vii, 200 p. ; 24 cm. -- (Research in teaching and learning : a project of the American Educational Research Association ; Vol. 2). -- Includes bibliographical references and index. -- ISBN 0028970063 ; (BB18500864) ; https://ci.nii.ac.jp/ncid/BB18500864 Author Heading(s): Linn, Robert L. ; Frederick Ericson. -- Classification(s): DC20 : 370.7/8073. -- Subject Heading(s): LCSH : Education -- Research -- United States ; LCSH : Teaching