by Abraham H. Birnbaum 
U.S. Army Personnel Research Office, Washington D.C. 
Abstract Human behavior in terms of actual performance has been investigated for the 
purpose of determining those photo characteristics that are best for the detection and iden 
tification of objects on photographs. Reported are the findings of a study of the relative 
merits of positive transparencies, negative transparencies, positive prints (non-stereo) and 
stereo prints. Four different sets of photographs varying in content and reproduced at two 
quality levels, were submitted to 64 experienced photo interpreters. Their performance was 
evaluated in terms of accuracy and completeness of their identification. 
Résumé Les possibilités humaines d’interprétation ont été étudiées pour déterminer quelles 
sont les meilleures caractéristiques photographiques de détection et d’identification d’objets. 
Il est fait mention ici des résultats d’une étude concernant les avantages relatifs de transparents 
positifs et négatifs, de copies positives (non stéréoscopiques) et de copies stéréoscopiques. 
Quatre jeux différents de photographies reproduits à deux niveaux de qualité furent soumis 
à 64 photointerprètes expérimentés. Les résultats de leur identification ont été jugés d’après 
leur précision et leur degré de perfection. 
Zusammenfassung Es wurde die menschliche Leistungsfähigkeit untersucht, mit dem 
Zweck, diejenigen Luftbild-Eigenschaften festzulegen, welche für die Entdeckung und Be 
stimmung von Einzelheiten in den Luftbildern am geeignetsten sind. Es wird das Ergebnis 
einer Studie besprochen über den relativen Wert von Positif- und Negatif-Transparenten, 
Positif-Einzel-Abdrücken und Positif-Stereo-Abdrücken. Vier Photo-Spiele, inhaltlich ver 
schieden und abgedruckt auf zwei Qualität-Niveaus, wurden von 64 Beobachtern untersucht 
und die Ergebnisse hinsichtlich Genauigkeit und Vollständigkeit überprüft. 
Until fairly recently very little was known about basic psychological factors 
in image interpretation, particularly in the operational setting. To fill this gap 
the United States Army Personnel Research Office formulated a program to 
answer the question: What are the skills, abilities and techniques that are 
necessary to detect and identify objects on photographs. 
In the implementation of our research program we have paid particular 
attention to problems that dealt with determination of how interpreters can 
best use the imagery, equipment, time, and skills to extract useful information. 
Prior studies dealt with performance as a function of viewing time, repeat 
exposure to imagery, and team work procedures. The effort of these studies 
was directed primarily towards gaining insight into how interpreter performance 
might be improved via the mechanism of improving techniques and procedures 
of interpreter operations. We were, however, not unaware of the fact that the 
nature of the stimulus material itself has an impact on performance. This 
paper will deal primarily with interpreter performance as a function of selected 
photo display characteristics. The study is concerned with the relative merits 
of positive transparencies, negative transparencies, positive prints (stereo) and 
positive prints (non-stereo). 
EFFECT OF SELECTED PHOTO CHARACTERISTICS 
ON DETECTION AND IDENTIFICATION