The psychological factors of HDTV and stereoscopic (3-D) HDTV are discussed, as well as the applicability of a one-dimensional quality grading scale, which is often used in evaluating picture quality, to an evaluation of the overall impressions is studied. First, HDTV and 3-D HDTV sequences were analyzed with the Semantic Differential (SD) technique and factor analysis. Eight factors were obtained separately for each kind of television. Next, the relationship between the opinion scores obtained using a seven-grade quality scale and the factor scores was examined for representation by multiple regression models. Consequently, the regression model was found to be applicable to the scores for HDTV sequences and to be inapplicable to those for the 3-D HDTV sequences. The “Naturalness” (Sense of naturalness) from the 3-D HDTV was found to be closely related to the disparity.