ICONIC SIGNS AND STOCK FLOW PERFORMANCE
Friederike Brockhaus Peter Sedimeier
Chemnitz University of Technology, Germany
Department of Psychology
Chemnitz University of Technology
09107 Chemnitz, Germany
Phone: ++49-371-53137111
Fax: ++49-371-5318 37111
Email: friederike.brockhaus@psychologie.tu-
chemnitz.de
Chemnitz University of Technology, Germany
Department of Psychology
Chemnitz University of Technology
09107 Chemnitz, Germany
Phone: ++49-371-53136431
Fax: ++49-371-27469
Email: peter.sedlmeier@psychologie.tu-chemnitz.de
Keywords: Stock and Flow systems, pictograms/ iconic signs, representation format
In our lives, it is very important to understand Stock and Flow (SF) systems. But in
many studies, a large number of participants failed finding out the stock’s pattern when
in- and outflow were given (e.g. Booth Sweeney & Sterman, 2000). Different
modifications of the flows' representation were tested to improve SF performance, but
they did not help (much) (e.g. Cronin, Gonzalez, & Sterman, 2009). One modification
led to strongly improved performance: instead of line graphs, diagrams including
Pictograms (iconic signs) were shown (Brockhaus, Arnold, Schwarz, & Sedlmeier,
2013). In follow up studies, performance still was better for iconic signs, but the effect
decreased (e.g. Brockhaus & Sedlmeier, 2018). In the present study, we tried to
overcome some shortcomings of the preceding studies. E.g. in one study each
participant had to solve two identical flow patterns as tasks, one shown with pictograms
and one with line graphs. The solution rates of the two patterns correlated highly. It was
not clear, if participants realized the flow patterns being identical. We wanted to find out
if the facilitating effect of using iconic signs could be replicated. We designed the
diagrams including iconic signs according to ISOTYPE (Neurath, 1936). Furthermore,
we changed the iconic format again to find out, if more abstract signs (plus and minus
for inflow and outflow) work as well as the iconic signs with babies representing births
and coffins representing deaths as used in preceding studies.
Methods: 25 participants solved two tasks with identical flow patterns but different
representation format (line graph vs. iconic signs special or general (fig.1)) and a third
SF task (with sawtooth pattern as used by Booth Sweeney & Sterman, 2000) between
the tasks with identical flow patterns in order to test if participants realized the first and
third task being identical by asking them to rate the similarity of the three tasks.
rms ohne
ese eeeeeee E
ee
The baseline condition with line
graph: grey for birth rates and
black for death rates (modified
from Cronin et al., 2009).
The condition with iconic signs
special (Arntz, G. "Pictograms*
(Babies and coffins) / © VG
Bild-Kunst, Bonn 2018).
The condition with iconic signs
general: babies for births were
substituted by signs of plus and
coffins for deaths by minus.
Figure 1. Flow graphs of the discontinous task represented in three different formats
We also controlled the variables gender and mathematical skills since both correlated
in the past with SF performance (e.g. Kapmeier, 2004; Lungwitz, Sedlmeier & Schwarz,
2018). The dependent variable was the rate of correct solutions.
Results: Taken together, the solution rates did not differ: In the conditions with
iconic signs, 36% answered both questions about the stock correctly. In the line graph
condition, 32% and 24% respectively answered the questions about the stock correctly.
When separated by position, differences depending on the used format can be seen (fig.
2). Participants working on iconic signs first showed better solutions than those starting
with line graphs. This still can be seen for the “maximum of stock” when the same task
(same pattern but different representation format) was shown again at third position.
[1 © stock maximal
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Correct solutions - mean
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02
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line iconic signs line iconic signs
Solutions of diagrams at first position Solutions of diagrams at third position
Figure 2. Bar plot showing the mean of the correct solutions for maximal and minimal stock, including 90%
confidence intervals; separated by position and format.
Regression analyses were conducted including representation format at first position,
gender, and mathematical skills as independent variables. The dependent variable was
the rate of correct solutions. R? = .42 was significantly different from zero with F(3,23)
= 4.779, p = .01. Gender was the most important predictor (gender: B = .54, p = .01 with
males performing better). Iconic signs at first position led to better solutions (8 = .45; p
= .02); and higher mathematical skills led to better solutions (B = .31, p = .10). No
meaningful differences between the two types of iconic signs could be seen. Moreover,
the solutions rates for the discontinuous task in first and third position correlated highly.
The participants also had to judge how similar they had perceived the three tasks. Only
about one fifth realized the similarity of the first and third task, therefore realizing this
seems not to explain the high correlation of solutions completely.
Taken together, it seems that if one wants to achieve higher solution rates in SF
related problems, one has to do more than changing the representation format of the
flows. But it also seems that one can improve basic SF performance by using iconic
signs for the flows.
REFERENCES
Arntz, G. (2018). "Pictograms“ (Babies and coffins) / © VG Bild-Kunst, Bonn.
Booth Sweeney, L. B. & Sterman, J. D. (2000). Bathtub dynamics: Initial results of a
systems thinking inventory. System Dynamics Review, 16, 249-286.
Brockhaus, F. & Sedlmeier, P. (2018). Diagrams including pictograms increase Stock-
Flow Performance. In Chapman, P., Stapleton, G., Moktefi, A., Perez-Kriz, S.. &
Bellucci, F. (eds) Diagrammatic Representation and Inference. Diagrams 2018. Lecture
Notes in Computer Science, vol 10871. (pp. 704-707). Springer, Cham.
Brockhaus, F. & Sedlmeier, P. (under review). Using pictograms improves the
understanding of Stock&Flow-Systems.
Brockhaus, F., Arnold, J., Schwarz, M.A., & Sedlmeier, P. (2013). Does the
modification of the representation format affect Stock-Flow-Thinking? Paper presented
at the Proceedings of the 31st International Conference of the System Dynamics Society
in Cambridge, MA, USA.
Cronin, M., Gonzalez, C., & Sterman, J. D. (2009). Why don’t well-educated adults
understand accumulation? A challenge to researchers, educators and citizens.
Organizational Behavior and Human Decision Processes, 108, 116-130.
Kapmeier, F. (2004). Findings from four years of bathtub dynamics at higher
management education institutions in Stuttgart. Paper presented at the 22nd
International Conference of the System Dynamics Society, Oxford, England, UK.
Neurath (1936). International Picture Language. London: Kegan Paul.
Lungwitz, V., Sedlmeier, P., & Schwarz, M. (2018). Can gender priming eliminate the
effects of stereotype threat? The case of simple dynamic systems. Acta Psychologica,
188, 65-73.
