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Effect of framing on the perception of genetic recurrence risks.

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American Journal of Medical Genetics 33: 130-135 (1989)
Effect of Framing on the Perception of -Genetic
Recurrence Risks
Shoshana Shiloh and Michal Sagi
Institute for Child Development, Sheba Medical Center, Tel-Hashomer, and School of Education, Tel-Aviv University (S.S.)
and Department of Human Genetics, Hadassah Medical Center, Ein-Kerem, Jerusalem (M.S.), Israel
Individuals asked to evaluate genetic recurrence risks were found to be influenced by
the way the risks were framed. Presenting a
single risk figure resulted in overweighting
of low probabilities and underweighting of
high probabilities, as compared to presenting
a list of sequential risks. Differences were
also found between meanings attached to verbal expressions of risks when translating
from verbal to numerical expressions, and
vice versa. The implications of these findings
for genetic counseling are discussed.
vational factors have been implicated in the process of
recurrence risk perceptions, including binary transformations, scenario presentations, prior expectations, and
reproductive motivations [Lippman-Hand and Fraser,
197913; Shiloh and Saxe, 19881. The present study was
undertaken to determine how risk perceptions are influenced by the way they are presented to individuals. This
is a particularly important factor, since it is completely
controlled by the genetic counselor.
There is ample evidence that even subtle changes in
the way risks are expressed can have a major impact on
perceptions and decisions. Numerous examples of these
“framing effects” have been demonstrated by Tversky
and Kahneman [1981] and Slovic et al. [1982]. For exKEY WORDS: risk perception, framing efample, McNeil et al. [1982] found that presenting treatfects, genetic counseling
ment alternatives for lung cancer in terms of survival
rates versus death rates caused a dramatic shift in preferences.
INTRODUCTION
Manner of presentation was also suggested to influence
Providing information on recurrence risks is a major how risk information is interpreted in genetic counseling
component of genetic counseling. This information is [Pearn, 19791. Kessler and Levine [1987] recently comconveyed in order to provide a basis on which counselees pared percentage and odds presentations and found that
can make informed decisions about very important per- some individuals use a “number strategy” and therefore
sonal matters such as marriage and childbearing. Several interpret the percentages as representing higher risk,
studies have shown that risk information is interpreted while others use a “person strategy” and evaluate odds
by counselees in a personal manner and that their deci- as indicating a higher risk.
sions are related to their subjective perceptions of recurWe chose to study two other modes of presentation of
rence risks rather than the “objective” risk [Lippman- risk in genetic counseling: single versus sequential, and
Hand and Fraser, 1979a; Wertz and Sorenson, 1984; numerical versus verbal. A recurrence risk can be preShiloh and Saxe, 19881. These findings are consistent sented either as a single figure or in comparison to a
with general rules of decision-making under risk, as for- variety of genetic risks, such as risk in the general popmulated by Kahneman and Tversky [ 19791 in their “pros- ulation or in other genetic conditions. Many counselors
pect theory.” This model describes how prospects-beprovide some comparative data, but there are no definifore being evaluated-are psychologically represented tive guidelines regarding its importance and influence.
through the application of several editing operations.
Thus, we have set out here to compare people’s reactions
The primary importance of subjective perceptions of to single versus sequential presentations of recurrence
recurrence risks makes it essential to understand the risks.
factors that influence them. Some cognitive and motiRecurrence risks can also be presented verbally or
numerically. Counselors usually avoid verbal expressions
of risk, such as “high,” “doubtful,” “low,” and “unlikely,”
in an attempt to avoid judgmental and directive counseling [Hsia, 19791. Verbal expressions (which are also
Received for publication September 12, 1988; revision received
referred to as “qualitative expressions”) are not comDecember 16, 1988.
Address reprint requests to Shoshana Shiloh, Ph.D., Institute pletely missing in genetic counseling; however, counselors do use them when referring to extreme risk figures,
for Child Development, Sheba Medical Center, Tel-Hashomer
52621, Israel.
or when asked directly for a verbal evaluation by the
0 1989 Alan R. Liss, Inc.
Framing Effects in Risk Perceptions
counselee, or when trying to correct a seemingly biased
perception by the counselee [Carter et al., 1971; Emery,
1977; Lippman-Hand and Fraser, 1979al. Verbal expressions are almost always used by the counselees in their
discussion of recurrence risks with their counselors.
Therefore, we considered it informative to compare
meanings attached to risk numbers versus words, and to
assess whether translation of an expression from one
mode to the other changes its meaning.
MATERIALS AND METHODS
Subjects
Undergraduate and graduate students in Psychology,
Educational Counseling, and Medicine at Tel-Aviv University and The Hebrew University of Jerusalem participated voluntarily in the study.
Design and Procedure
A two-group experimental design was employed in each
study. Subjects were randomly assigned to an experimental group. No subject took part in more than one study.
131
Some such verbal expressions of genetic risks are
presented here. You are requested to write down for
each expression a percentage or percentages that seem
to you equivalent to that verbal expression of genetic
risk. You may use any percentage in more than one
category.” Nine expressions were presented very low,
quite low, less than moderate, moderate, above moderate, quite high, high, very high. The median was
recorded for answers given as ranges of percentages:
thus, 0-5% was coded as 2.5%.
2. The instructions for the numerical-to-verbal experiment were: “In genetic counseling a family is informed about their risk of having a child with a genetic
disorder or disease. The risk is presented in percentages. These percentages can be interpreted differently
(in words such as high or low) by different individuals.
Some risk categories are presented here (in percentages). You are requested to write down, for each category of genetic risks, a verbal expression (e.g., very
high, very low) which seems to you equivalent to these
percentages. You may use any expression for more
than one category.” Eight categories were presented,
covering the full range of probabilities: 0-3%, 4-796,
8-12%, 13-20%, 21-30%, 31-50%, 51-70%, 71-100%.
Study 1: Single Versus Sequential Presentation of
Risk Factors
A short questionnaire was designed, asking subjects to
The median percentage of each category was recorded
evaluate specific recurrence risks, given in percentages, for data processing. Verbal expressions given by respondcn an 11-point Likert scale (1 = very low, 11 = very ents were coded according to the same categories defined
high). Two versions of the questionnaire were prepared above in the verbal-numerical experiment. When a verbal
and administered to two different experimental groups, expression other than the nine listed ones was used, it
as follows:
was evaluated by two independent judges (social psy1. Thirty-seven subjects received the “sequential” chologists), and assigned to one of the categories. Agreequestionnaire consisting of nine objective risk figures ment between judges reached 94%. Cases of disagreement
presented in a sequential manner: I%,5%, lo%, 15%, were resolved by discussion prior to substantial analysis
25%, 35%, 50%, 70%, 90%.
of data. Expressions such as “almost certain” or “tremen2. Nine “single” questionnaires were prepared, each dous” were assigned to the “very high” category; “very
dealing with one recurrence risk and administered to unlikely” was coded as “very low.” These procedures
a group of 19-21 subjects (total 180 subjects).
permitted comparison between numerical values attached
to specific verbal expressions for both experiments.
Subjects were instructed as follows:
RESULTS
In genetic counseling a family is informed about their
risk of having a child with a genetic disorder or disease.
Table I summarizes the subjective interpretations of
The risk is usually expressed in percentages. A list of recurrence risks presented in the “single” versus the
such genetic risks is presented below. (In the “single”
study: one family was given a risk of . . .%). You are
TABLE I. Interpretations of Recurrence Risks in “Single”
requested to evaluate how this (these) risk(s) seem high
and “Sequential” Modes of Presentation
or low to you, by putting an x on the line(s).
Study 2: Verbal Versus Numerical Presentation
of Risk Factors
Two questionnaires were designed, one to assess the
translation from verbal to numerical probabilities and
the other to assess the translation from numerical to
verbal expressions. Each questionnaire was given to a
group of 24 students.
1. The instructions for the verbal-to-numerical experiment were: “In genetic counseling a family is informed about their risk of having a child with a genetic
disorder or disease. The risk is presented in percentages. These percentages can be interpreted differently
(in words such as high or low) by different individuals.
Subjective interpretations
Recurrence
risk (%)
1
5
10
15
25
35
50
70
90
* P < .05.
** P < .O1
Single
presentation
mean & SD
(n = 19-21)
Sequential
presentation
mean +- S D
(n = 37)
5.09 & 2.51
6.74 -C 2.85
7.58 t 1.95
8.00 f 1.89
8.05 f 1.55
8.84 & 1.39
9.21 & 1.27
9.68 t 1.06
9.95 +- 1.32
3.19 t 1.98
4.78 f 2.02
5.97 k 1.93
7.00 t 1.73
7.69 t 3.09
8.73 f 1.43
9.40 t 1.04
10.32 t 0.75
10.92 t 0.28
t
2.99**
2.67**
2.91**
1.93*
0.57
0.28
0.56
2.35*
3.25**
Shiloh and Sagi
132
“sequential” mode. There were significant differences
between the two modes of presentation a t the ends of the
scale. Single presentations of lower recurrence risks (up
to 15%) were assigned higher values of risk by the subjects, while single presentations of higher risks (70% and
over) were assigned lower values of risk by the subjects.
The subjective interpretation of risk in both modes of
presentation increased in direct relation to the objective
risk. This was determined by calculating the Pearson
correlation coefficients between objective risks and subjective interpretations: the results were 0.86 for the single
mode and 0.93 for the sequential mode. A logarithmic
relationship between objective and subjective risks was
observed in both modes of presentation. Increases in
subjective interpretations of risks were much steeper in
the lower range of risks than in the higher range. In the
single presentation mode, nearly the same increase in
subjective scale points was obtained between 1%and
10% and between 10% and 90%. In the sequential presentation mode, the increase obtained in subjective interpret.ations between 1%and 15% was equivalent to that
obtained between 15% and 90%. However, as illustrated
in Figure 1, the regression line in the sequential group is
much steeper than the regression line in the single group.
This explains the increasing differences in interpretations toward the extreme ends of the recurrence risks
and the crossing over of interpretations at about 40%
risk.
Table I1 and Figure 2 present data comparing the
translations of numerical-to-verbal and verbal-to-numerical expressions of risk.
Subjects assigned a higher numerical risk when translating from words to numbers than from numbers to
TABLE 11. Recurrence Risks Attached to Verbal
Expressions: Translation of Numerical to Verbal and Verbal
to Numerical Risk Expressions
Numerical risk (%)
Verbal to
numerical
Verbal exmession Mean f SD
Very- high
68.25 t
26.63
62.13 f
Hieh
28.12
Quite high
55.29 t
29.21
Above moderate
46.70 k
24.85
Moderate
33.85 f
16.67
Less than moderat,e 25.23 k
14.70
Quite low
14.39 +8.81
Low
7.73 +5.34
Very low
3.85 +3.25
* P < .05.
** P < .O1
-
Numerical to
verbal
n Mean f SD n
t
24 52.58 t 25.52 80 2.61*
24 23.90 t 19.48 38 6.33**
24 26.93 f 16.89 7 2.43*
24 21.50 2 9.62
8 2.77**
23 10.96 f 6.09 14 4.92**
22 13.25 t 3.25
2 1.13
22 4.92 2 2.89
6 2.56”
24 4.41 f 2.61 21 2.59*
23 2.12 k 1.44 13 1.81
100-
Y
u)
._
80-
11
VJ
=
.-0
10
U
m
very
low
9’
U
?!
8.
L
Q)
7.
”
P
0
.-Q)
0
3
v)
‘Y
3
t
1 5 1015
quite Less mo e more
Low
*
than r a k - than
moderate
moderate
*.
hi&
very
.--
high
*
I.
Fig. 2 . Verbal and numerical expressions of genetic recurrence risks.
-,
Numerical-to-verbal (frequency of expression use-in parentheses); - - - - - - -, verbal-to-numerical ( n = 24). * P < .05; **P < .01.
U
U
LOW
25
35
50
Recurrence
70
Risks
*
90
(%)
Fig. 1. Subjective interpretations of recurrence risks: Sequential
presentations ( n = 37) versus single presentations ( n = 19-21). -,
Sequential presentation; -----,
single presentation.
words. This held for all nine of the verbal expressions,
and was statistically significant for seven of them. “High”
risk produced the most dramatic results: translating this
verbal expression into numbers resulted in a mean risk
value of 62.13%. On the other hand, when translating
from numbers to words, the expression “high” was assigned to much lower risk values: mean 23.90%.
The data also show that subjects tended to use relatively few verbal categories in response to numerical
stimuli: they responded with a mean of 4.88 verbal categories for eight numerical categories. And, most of their
responses were extreme; for example, 24 subjects used
the expression “very high” 80 times, “moderate” 14 times,
Framing Effects i n Risk Perceptions
and “low” 21 times. The spontaneous use of numerical
categories in response to verbal expressions was much
more varied mean 8.46 numerical in response to nine
verbal categories.
DISCUSSION
Our results support the hypothesis that the way in
which genetic recurrence risks are presented (i.e., single
risk figures versus a sequence of risks, verbal versus
numerical expressions) determines the meanings attached to these risks. Presenting recurrence risks as
single figures resulted in overweighting of low probabilities (less than 25%) and underweighting of high probabilities (over 70%), indicating an insensitivity to increasing values of recurrence risks. This effect was diminished
when a recurrence risk was presented with several other
risks.
Insensitivity to statistical information has been found
in other cognitive-psychological studies as well [Lyon
and Slovic, 1976; Kahneman and Tversky, 19731. Fischhoff et al. [1979] argued that this insensitivity to
statistical information is due to the between-subject designs employed in these studies, exposing participants to
only one value of the statistical information. Such a
procedure tends to ensure low salience of the statistical
information, thereby reducing the likelihood of it being
used. It follows that respondents’ tendency to use statistical information could be increased by providing this
information in a within-subjects design, which exposes
them to several different values of the statistical variable.
A series of experiments designed to test these ideas
confirmed them [Fischhoff e t al., 19791, and our findings
also support this cognitive rule. These processes are
influenced by the way information is framed and can
explain why the adverseness of a small chance of a severe
loss is amplified and the value of long shots is enhanced
[Kahneman and Tversky, 19841.
This framing effect can also explain some findings
obtained in other studies on genetic counseling. Wertz et
al. [1986] found a “flat” curve for the modal category of
interpretation of risks between 10% and 50% for counselees, and between 25% and 50% for counselors. This
“flatness” can be due to insensitivity to the statistical
information, caused by presentation of single risk figures
without a comparison to other recurrence risks. This
notion requires further study within the context of genetic counseling, and its effect should be tested on counselors as well as on counselees. We suggest exploring the
possibility that some gaps in interpretation between
counselors and counselees arise because counselees, unlike counselors, are exposed to single risk figures.
The logarithmic nature of the relationship obtained
in both modes of presentation between objective risks
and subjective interpretations is equivalent to a phenomenon discovered in perceptual judgments and known as
Weber’s Law [Fechner, 18601. This law states that a
change in stimulus intensity, in order to be detected,
must be a constant percentage of the initial value. Therefore, slight changes are sufficient for detection at lower
stimulus intensities, and larger changes in stimulus intensity are required for detection as the baseline stimulus
133
becomes higher. We observed the same trend, with the
stimulus being the objective risk and perceptions being
the subjective interpretations. We suggest that interpretations of genetic risks are subject to these same general
rules of perception, which may explain some of the findings in studies on genetic counseling, irrespective of the
personal meanings attached to the stimulus.
Risk perceptions were affected by the use of verbal as
opposed to numerical expressions. Words such as “high”
and “low” to describe probabilities were found to have
different meanings when spontaneously ascribed to numerical probabilities than when read directly and translated into percentages. Subjects attached lower percentages to verbal expressions of probabilities used by themselves, and higher numerical values to verbal expressions
presented to them (except for the “very low” category).
For example, when subjects used their own words, the
term “high risk” had an average risk value of 23.90%;
when subjects ascribed a numerical value to the given
term “high risk”, the average value was 62.13%. “Low
risk” presented verbally earned a mean numeric value of
7.73%; when asked to ascribe words to numbers, “low
risk” scored 4.41%.
This finding might stem from the different cognitive
processes applied in active versus passive use of language
[Clark and Clark, 19771, and/or the different perspectives
of actor-observer behavior [Jones and Nisbett, 19711. We
suggest that given verbal expressions are interpreted by
their “lexicographic” (dictionary) meaning-“When you
say high risk you mean something over 60%.” On the
other hand, active use of verbal expressions denotes its
personal meaning-“25% is ‘high risk’ for me.” Another
explanation may reside in the nature of the experimental
situation. Subjects requested to use numerical expressions, which is not their natural language, try to be more
objective and precise and therefore less personal. Subjects
requested to use verbal expressions tend to express more
of their personal feelings.
Cognitive studies performed on the verbal-numerical
probabilities distinction have produced mixed results.
Most individuals use verbal terms when spontaneously
expressing their opinions about probabilistic events, but
most decision-makers prefer to receive numerical probabilities [Erev and Cohen, in press]. Considerable interpersonal variance has been found in the meanings ascribed to words used to define probability [Lichtenstein
and Newman, 19671. High consistency was found in
interpretations of these expressions by specific individuals, leading to the conclusion that numerical rather than
verbal expressions should be used for communication
[Bryant and Norman, 19801. The effectiveness of the two
modes of presentation for decision-making purposes remains unclear. Zimmer [1983] suggested that people are
less likely to make judgmental biases using verbal than
numerical expressions. Budescu et al. [ 19881 found that
numerical expressions were better, and Erev and Cohen
[in press] found no difference in the efficiency of the two
modes of presentations. The verbal-numerical distinction
was found in our study to be highly relevant for genetic
counseling. Further research is required to elucidate its
effect on the communication and decision-making in
genetic counseling.
134
Shiloh and Sagi
Another interesting finding was that in translating
from numbers to words, fewer and more extreme categories were used. This is consistent with the findings of
Cohen et al. [1985] that: “in the domain of losses, subjects’ choices are not made on the basis of the precise
probabilities of relevant events but on the basis of vague
categories of, say ‘belief which they assign to these
events” (p. 220). These verbal categories appeared to be
extremely coarse for some individuals.
This phenomenon can also explain the tendency of
genetic counselees to transform recurrence rates into
binary perceptions (whether it will or will not happen).
Described by Lippman-Hand and Fraser [ 1979b], this
can be viewed as an expression of the basic cognitive
process of translation of risks from numerical to verbal
language. It can be assumed that a personal meaning is
added in these translations, which tends to yield more
extreme interpretations, and to reduce the number of
categories used. In our study, this tendency was found as
a cognitive process, without the emotional burden and
the personal consequences involved in the real genetic
counseling situation. The addition of an emotional factor
might have an amplifying effect (more extreme perceptions and less categories) on this basic cognitive process,
leading to the described binary perceptions.
The compatibility between our experimental results
obtained in a nongenetic population and observations
obtained in studies conducted in real genetic counseling
situations supports the generalizability of our results to
genetic counseling. However, a replication of our findings
in genetic counselees’ populations is recommended, although ethical considerations may complicate a design of
such a field study.
Practical Implications
The implications of our findings for genetic counseling
are straightforward. Presenting a recurrence risk of 5%
by itself would lead a counselee to perceive it as higher
than if it were presented in comparison with other recurrence risks. Single or compared presentations would not
make a difference in the 25-70% range. And, in the 70%
and higher range, a comparison to other risks would
result in higher risk perceptions.
The double meaning found for verbal probabilistic
expressions is also important for communication in
genetic counseling. Clarifying the differences between
sending and receiving a verbal message is essential for
ensuring reliable communication between counselor and
counselee. Antley [ 19791 argued that neutral information-giving in genetic counseling is not possible, partly
because the counselor chooses the portion of genetic
information to be provided, and that choice reflects his/
her own values. We suggest, in addition, that neutrality
of information-giving is also impossible because of the
framing effects involved in any mode of presenting risk
information. This property of genetic information-giving
has been described bv Kessler 11979. 19801 and was
referred to as metacommunication-the deeper, connotative level of communication, which includes the syn‘Ontext
in which it takes place’
tactic, physical, and
Formulation effects can Occur unconsciously without
anyone being aware of the impact of the frame on the
ultimate decision. They can also be used deliberately to
manipulate the relative attractiveness of options in various settings and in genetic counseling as well [Thaler,
1980; Kessler, 19811. We think that the genetic counselor,
as a professional, has an obligation to be aware of the
magnitude of framing effects of different presentation
modes of risk information. A list of framing effects of
genetic information, such as that demonstrated in the
present study and in the Kessler and Levine [1987] study
should be established. Following this, the positive and
negative presentations of recurrence risks should be studied, such as 25% for an affected child as opposed to 75%
for a healthy child.
An important issue raised here is the right way to
present recurrence risks, the implication being that there
is a right and wrong way of perceiving recurrence risks.
This assumption is not valid, since risk perception is a
multidimensional and personal process [Vlek, 19871. The
right way must be tailored for the individual counselee
and to specific counseling situations as part of the counseling process. Moreover, the counselor may choose to
present the information in more than one way during the
counseling process, according to the different needs and
concerns expressed by the counselee. Multimethods of
presentation may serve as a powerful technique for clarifying risk information and for helping clients gain a
better understanding of the personal meaning of the
information. Divergent presentations are also recommended as a means to overcome judgmental biases and
to enhance objectivity in communication [Tversky and
Kahneman, 19811. Finally, in this study we dealt with
the communicational properties of risk perception. A
complete picture of this issue should take into consideration the personal level as well, and more research is
required to determine the interactions between presentation modes and other relevant factors for risk perception, such as prior expectations [Shiloh and Saxe, in
press], personal cognitive styles [Kessler and Levine,
19871, or emotional states [Antley, 19791.
REFERENCES
Antley RM (1979):The genetic counselor as facilitator of the counselee’s
decision process. In Capron AM, Lapp6 M, Murray RF, Powledge
TM, Twiss SB, Bergsma D (eds): “Genetic Counseling: Facts, Values,
and Norms.” New York Alan R. Lisa, Inc., for the National Foundation-March of Dimes. BD:OAS XV (2):137-168.
Bryant GD, Norman GR (1980): Expressions of probability words and
numbers. N Engl J Med 302411.
Budescu DV, Weinberg S, Wallsten TS (1988): Decisions based on
numerically and verbally expressed uncertainties. J Exp Psycho1
[Hum Percept] 14(2):281-294.
Carter CO, Fraser Roberts JA, Evans KA, Buck AR (1971): Genetic
clinic: A follow-up. Lancet 1:281-285.
Cohen M, Jaffrey JY, Said T (1985): Individual behavior under risk and
under uncertaintly: An experimental study. Theory Decision 18203228.
Clark HH, Clark EV (1977): “Psychology and Language: An Introduction t o Psycholinguistics.” San Diego: Harcourt Brace Jovanovich.
Emery AEH (1977): Changing patterns in a genetic counseling clinic.
In Lubs HA, de la Cruz F (eds): “Genetic Counseling.” New York:
Raven Press. pp 113-120,
Ere” I, Cohen BL: Verbal
numerical probabilities: Efficiency,
biases and the preference paradox. Organ Behav Hum Perform, in
press.
Framing Effects in Risk Perceptions
Fechner G T (1860): “Elements der Psychophysik.” Leipzig: Breitkopf
und Hartel.
Fischhoff B, Slovic P, Lichtenstein S (1979): Improving intuitive judgment by subjective sensitivity analysis. Organ Behav Hum Perform
23:339-359.
Hsia YE (1979): T h e genetic counselor as information giver. In Capron
AM, Lapp6 M, Murray RF, Powledge TM, Twiss SB, Bergsma D.
(eds): “Genetic Counseling: Facts, Values, and Norms.” New York:
Alan R. Liss, Inc., for the National Foundation-March of Dimes.
BD:OAS XV(2):169-186.
Jones EE, Nisbett R E (1971): “The Actor and the Observer: Divergent
Perceptions of the Causes of Behavior.” New York General Learning
Press.
Kahneman D, Tversky A (1973): On the psychology of prediction. Psych
Rev 80:237-251.
Kahneman D, Tversky A (1979): An analysis of decision under risk.
Econornetrica 47263-291.
Kahneman D, Tversky A (1984): Choices, values, and frames. Am
Psychol 39:341-350.
Kessler S (1979): T h e genetic counselor as psychotherapist. In Capron
AM, Lapp6 M, Murray RF, Powledge TM, Twiss SB, Bergsma D
(eds): “Genetic Counseling: Facts, Values, and Norms.” New York:
Alan R. Liss, Inc. for the National Foundation-March of Dimes.
BD:OAS XV(2):187-200.
Kessler S (1980): T h e psychological paradigm shift in genetic counseling.
SOCBiol 27:167-185.
Kessler S (1981): Psychological aspects of genetic counseling: Analysis
of a transcript. Am J Med Genet 8137-153.
Kessler S, Levine EK (1987): Psychological aspects of genetic counseling. IV. The subjective assessment of probability. Am J Med Genet
28361-370.
Lichtenstein S, Newman JR (1967):Empirical scaling of common verbal
phrases associated with numerical probabilities. Psychonomic Sci
9:563, 564.
Lippman-Hand A, Fraser FC (1979a): Genetic counseling: Provision
and reception of information. Am J Med Genet 3:113-127.
135
Lippman-Hand A, Fraser FC (1979b): Genetic counseling: The postcounseling period: I. Parents’ perceptions of uncertainty. Am J Med
Genet 4:51-71.
Lyon D, Slovic P (1976):Dominance of accuracy information and neglect
of base rates in probability estimation. Acta Psychol (Amst) 40:287298.
McNeil B, Pauker S, Sox H, Jr, Tversky A (1982): On the elicitation of
preferences for alternative therapies. N Engl J Med 306:1259-1262.
Pearn J (1979): Decision making and reproductive choice. In Hsia YE,
Hirschhorn K, Silverberg RL, Godmilo L (eds): “Counseling in Genetics.’’ New York: Alan R. Liss, Inc., pp 223-238.
Shiloh S, Saxe L (1988): Perception of risk in genetic counseling. Psychol
Health: An International J (in press).
Slovic P, Fischhoff B, Lichtenstein S (1982): Response mode, framing,
and information-processing effects in risk assessment. In Hogarth
R (ed): “New Directions for Methodology of Social and Behavioral
Science: Question Framing and Response Consistency.” San Francisco: Jossey-Bass, pp 21-36.
Thaler R (1980): Toward a positive theory of consumer choice. J Econ
Behav Organ 1:39-60.
Tversky A, Kahneman D (1981): The framing of decisions and the
psychology of choice. Science 211:453-458.
Vlek C (1987): Risk assessment, risk perception and decision making
about courses of action involving genetic risk: An overview of concepts and methods. In Evers-Kiebooms G, Cassiman JJ, Van den
Berghe H, d’Ydewalle G (eds): “Genetic Risk, Risk Perception, and
Decision Making.” New York: Alan R. Liss, Inc., for the National
Foundation-March of Dimes BD: OAS XXIII(2):171-207.
Wertz DC, Sorenson J R (1984): Genetic counseling and reproductive
uncertainty. Am J Med Genet 18:79-88.
Wertz DC, Sorenson JR, Heeren T C (1986): Clients’ interpretation of
risks provided in genetic counseling. Am J Hum Genet 39253-264.
Zimmer AC (1983): Verbal versus numerical processing of subjective
probabilities. In Scholz R (ed): “Decision Making Under Uncertainty.’’ Amsterdam: North Holland Publishing Co., pp 159-182.
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658 Кб
Теги
perception, effect, recurrent, framing, genetics, risk
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