E-module/knowledge clips week 5

Question 1

weber’s law

Answer 1

the amount of physical stimulus which is needed to increase to be just perceivable different
- is a constant linear ratio

Question 2

just noticable difference

Answer 2

difference between 2 stimuli that can be detected in 50% of the cases

Question 3

Fechner’s law

Answer 3

the subjective sensation is proportional to the logarithm of the stimulis intensity

Question 4

Steven’s law

Answer 4

method of magnitude estimation
- people can easily rate the intensity of 1 stimulus in proportion to the intensity of another stimulus

Question 5

staircase method

Answer 5

the next stimuli present is dependent on the response to the previous stimulus
- start with high, up with incorrect, down with correct

Question 6

up down transformed response

Answer 6

needs 2 correct answers to go up only 1 incorrect answer to go down

Question 7

detection threshold

Answer 7

minimal level of a stimulus that is distinguishable from water/air

Question 8

recognition threshold

Answer 8

minimum level that takes on the characteristic smell/taste of stimulus

Question 9

difference threshold

Answer 9

minimum level necessary in order to detect the change of 50% of the time (JND)

Question 10

general method of limits with threshold testing

Answer 10

= giving the stimuli one by one. panelist indicate whether they detect a taste
- stimuoli presented in ascending or descending way
- threshold: where reversal in judgment happens
- start with highest (or lowest) ever step take one other concentration
- issue = fatigue & different people set different criteria for the test

Question 11

context effect

Answer 11

perception of a certain object or stimulus depends on the context/environment

Question 12

contrast effect

Answer 12

people their judgement depends on the frame of reference
- 10 degrees cold here, not Antartica

Question 13

adaptation level theory

Answer 13

people get used, adapt to, certain levels of sensory intensity

Question 14

assimilation effect

Answer 14

context in which a products is placed affe ts food choice & evaluation
- label (wine from California/North Dakota)

Question 15

contrast vs. assimilation

Answer 15

small effect: rating same as anticipated
large effect: surprise evokes larger discordance leading to contrast

Question 16

halo effect

Answer 16

positive correlation between unrelated attributes. score high on 1, other attributes go up as well (vanilla)

Question 17

horns effect

Answer 17

opposite of halo. one’s perception of an attribute is due to a single negative attribute
(artificial flavour)

Question 18

dumping effect

Answer 18

when rating sweet fruit, don’t forget only rate sweetness, also intensity of fruit flavour.
- if not, people dump the perception of 1 attribute on another (false impressions)

Question 19

range principle

Answer 19

panelists tend to subdivide the total range of a scale into equal segments

Question 20

frequency principle

Answer 20

panelists tend to use the categories of a scala an equal number of times
- wider scale: wider answers

Question 21

centering bias

Answer 21

most panelists tend to center their responses around the middle of the scale
- avoid using left/lower parts (theory of parducci)
- hedonic scales: extremen not at the end, but a bit sooner

Question 22

acceptance testing

Answer 22

focuses on the degree of liking of a product
- 1 by 1 products
- how much do you like…

Question 23

preference testing

Answer 23

comparison between 2 products
- ask which you prefer
- form a rank-order testin

Question 24

variation on acceptance testing

Answer 24

1. speficic population
   - children: with pictures and 4/7 options
2. VAS
   - uses visual lines (pips, unmarked line, slam scale
3. labelled magnitude scale
   - anchors” most (dis)lied imaginable
4. Just about right scale
   - combination of intensity and hedonic liking
   - also gives info about direction & magnitude of the distances to optimal sensation