1. SUBJECTIVE APPRECIATION OF THE ARTIFICIAL LIGHT OsvaldoDA POS – Francesca TRERE- Francesco BIONDI University of Padua - Italy

2. Previous experiment. How false informations and stereotypes can influence the observer's evaluation of a light source? Material: - 4 (2 + 2) lamps - 4 presentations - 16 colour samples & atlas - 24 unipolar scales fot a semantic differential

3. Procedure: 20 observers had: - to read the lamp specifications - to peform the colour match - to fulfill the semantic differential - to express their impressions

4. I1F2I2F1 mean evaluations Scales of the semantic differential Artificial sources fresh superficial slow soft male clean heavy classic cold clear

5. Results.  No significant difference in the semantic differential for physically identical sources  Rather good colour constancy

6. Experiment 2. Differences:  Personal interview with 12 university students in their private study room and in public study rooms.  Students' actual choices.  Shorter list of bipolar scales.  Changes in the technical sheets.

7. Results.  Preference for combined diffuse and concentrated illumination  General preference for warm ilght  Comparison between private and public places illuminations  Again non difference for evaluations of physically identical lights, witn one exception (*clear – confusing)‏

8. y x Chromaticity of the lights in the public study places and in the private study rooms In a CIE1939 diagram

9. I1F2I2F1 mean evaluations SFslow fast SHsoft hard DCdirty clean HLheavy light CMclassic modern CWcold warm CCclearconfusing * Artificial sources Scales of the semantic differential

10. Conclusions.  Preference for diffuse + concentrated illumination  Preference for warm light  Selective preference for illuminations in public places  No influence of the manipulated informations on the students' evaluations