Information sufficiency is a concept defined as "an individual's assessment of the amount of information he or she needs to cope with…risk" (Griffin, Neuwirth, Dunwoody, & Giese, 2004, p. 24) and is central to the risk information seeking and processing model (RISP, Griffin, Dunwoody, & Neuwirth, 1999). The concept is linked to the idea of sufficiency threshold in the Heuristic-Systematic Model (HSM, Eagly & Chaiken, 1993). Specifically, information sufficiency is "the amount of information people say they need to deal adequately with a given risk in their own lives" (Griffin, et al., 2004, p. 26).
The sufficiency principle in the HSM argues that people attempt to balance exerting cognitive effort and maximizing confidence in a given judgment (Chaiken, Giner-Sorolla, & Chen, 1996; Chaiken, Liberman, & Eagly, 1989). The sufficiency threshold is an individual's desired confidence level, or the point at which individuals feel confident that a judgment satisfies their current motives. Typically, individuals will exert sufficient cognitive effort until their level of confidence reaches their sufficiency threshold. Thus, the sufficiency principle is based on two levels of confidence: the level of confidence an individual has in a judgment and the level of confidence an individual desires in a judgment.
In the context of risk and information seeking, the sufficiency threshold would be individuals' level of confidence they have in the knowledge they hold about a given risk. If individuals feel they don't have the knowledge to meet that threshold, then the resulting gap should motivate them to seek out more information about the risk.
In the RISP model, information sufficiency and information gathering capacity impact the extent to which individuals seek out risk information in both time and effort.
In practice, information sufficiency has been measured as information insufficiency, meaning the gap between a person's knowledge about a risk and the amount of information the person feels he or she needs to adequately deal with the risk.
Griffin et al. (2004) measured information insufficiency with two self-report variables, both measured on a 0 to 100 scale. The contexts were 1) eating either Lake Michigan or Lake Erie fish, or 2) drinking either Lake Michigan or Lake Erie tap water.
- Perceived current knowledge about a risk
"…we would like you to rate your knowledge about this risk. Please use a scale of 0 to 100, where 0 means knowing nothing and 100 means knowing everything you could possibly know about this topic. Using this scale, how much do you think you currently know about the risk from [state the risk]?"
- sufficiency Threshold
"Think of that same scale again. This time, we would like you to estimate how much knowledge you would need to deal adequately with the possible risk from [state the risk] in your own life. Of course, you might feel you need the same, more, or possibility even less, information about this topic. Using a scale of 0 to 100, how much information would be sufficient for you, that is, good enough for your purposes?
An important point about analysis: Given the definition that information (in) sufficiency is operationally the difference between perceived knowledge and sufficiency threshold, it seems that information sufficiency could be calculated by subtracting sufficiency threshold from knowledge. If knowledge exceeds the threshold, then information sufficiency would be positive, indicating that individuals perceive that they know "enough" about the risk and would not feel they had to engage in additional information seeking. If sufficiency threshold exceeds knowledge, then information sufficiency would be negative, indicating that individuals perceived that they don't know enough about the risk, and would thus feel they need to gather more information. However, Griffin et al. (2004) chose to analyze their data differently.
Griffin et al. (2004) opted to run a structural equation model (SEM, using LISREL), with the sufficiency threshold variable as the criterion and current knowledge as a control variable. This analytic strategy has several advantages over the method of using the sufficiency threshold-current knowledge difference score as the criterion. SEM permits the stringent evaluation of the hypotheses through simultaneous control of other variables in the model and reduces the reliability and floor/ceiling effect issues of employing two single measures.
Rationale for selection
The two-item measure developed by Griffin et al. (2004) is the only multiple item measure found that was used in a health risk context. The questions are short and easily answerable.
Since the Griffin et al (2004) measure is not comprised of an index of several items, estimates of internal consistency (i.e., Chronbach's alpha) are not calculable. Other estimates of reliability (e.g., test-retest) currently do not exist.
- Measure is Short
- Questions are easily answered
- Reliability not assessed
- Validity not assessed
Use of measure (with examples)
Griffin et al. (2004) found that perceived severity of the risk and worry about the risk were positively related to information insufficiency. Information subjective norms (measured as agreeing with "people who are important to me would expect me to stay on top of information about [the risk]") were also positively related to information insufficiency. This means that individuals who had the largest information insufficiency (who felt they knew less about the risk compared to what they felt they needed to know) also perceived the risk as more severe, worried more about the risk, and believed that knowing about the risk was the norm.
Trumbo (2002) measured sufficiency with a single item measured on a 7-point Likert type question: the information I have at this time meets all of my needs for knowing about the issue of a possible cancer cluster (the particular risk under study). He found that ability (feeling capable of finding and using information) was positively associated with sufficiency and that sufficiency positively predicted heuristic processing across three communities. Trumbo's single-item measure may be suitable for some research purposes, especially if the interest is in the gap between what individuals think they know and what they think they need to know. In this case, the values of each perception (current knowledge and sufficient knowledge), would not be attained and compared. No research currently exists that compares the effectiveness of the two-item measure to the single-item measure.
One notable outcome that was not the focus of their study (and thus, not discussed) is the positive relationship between current knowledge and sufficiency threshold (r = .27, p<.001, Griffin, 2009). This suggests that as current knowledge increases, so does the sufficiency threshold, which indicates that the more individuals thought they knew about a particular risk, the more they felt they needed to know to adequately deal with the risk. However, this result may be idiosyncratic to the particular study. The authors note (Griffin et al., 2004, p. 54) that current knowledge and sufficiency threshold need not be correlated.
Information sufficiency should be partially dependent on the level of uncertainty a person is willing to hold. Further, information sufficiency is dependent on perceived knowledge about a risk, not actual knowledge. If a person thinks he or she is very knowledgeable about a risk (regardless of actual knowledge) compared to the level of knowledge the person think he or she needs, then the information insufficiency should be low and the person would be less motivated to seek additional information about the risk.
Chaiken, S., Giner-Sorolla, R., & Chen, S. (1996).Beyond accuracy: Defense and impression motives in heuristic and systematic in formation processing. In P.M. Gollwitzer & J.A. Bargh (Eds.),
The psychology of action: linking cognition and motivation to behavior (pp. 553-578). New York: Guilford.
Chaiken, S., Liberman, A., & Eagly, A.H. (1989).Heuristic and systematic processing within and beyond the persuasion contexts. In J. S. Uleman & J.A. Bargh (Eds.),
Unintended thought (pp. 212-252). New York: Guilford.
Eagly, A.H., & Chaiken, S. (1993).The psychology of attitudes.
For Worth, TX: Harcourt Brace.
Griffin, R.J. (August 4, 2009).Personal communication.
Griffin, R.J., Dunwoody, S., & Neuwirth, K. (1999).Proposed model of the relationship of risk information seeking and processing to the development of preventive behaviors.
Environmental Research, 80, S230-245.
Griffin, R.J., Neuwirth, K., Dunwoody, S., & Giese, J. (2004).Information sufficiency and risk communication.
Media Psychology, 6, 23-61.
Trumbo, C.W. (2002).Information processing and risk perception: An adaptation of the Heuristic-Systematic Model.
Journal of Communication, 52, 367-382.