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Mark học AIThe IKEA Effect · Michael Norton, Daniel Mochon and Dan Ariely
Does making something with your own hands make you value it more than an identical thing someone else made? The answer: yes, moderately, but only if you finish it. And that same "valuing it more" makes us misjudge our own work.
Experiment 1A: 52 students and a plain black storage box bought from an IKEA store (Norton et al., 2012).
The three explanations do not yet agree. What they share: what we make becomes part of "me", so we see it with different eyes.
10 common claims about the IKEA effect, checked against current research. Click each line for the reasoning.
All four original experiments point the same way (Norton et al., 2012). An independent team in Germany replicated it (Sarstedt, Neubert and Barth, 2017). A meta-analysis of 55 studies and 5,454 people finds a moderate effect, d = 0.57 (Pelled, 2023).
The Lego experiment (118 people) and the unfinished-box experiment (39 people) reach the same conclusion (Norton et al., 2012). This is the most important part for the workplace.
Origami folders thought others would bid as much as they did (Norton et al., 2012, a side group of 14). Outside the lab, creators overestimated how well their own acts would do (Berg, 2016, 339 circus professionals).
The original samples were small (39 to 118 students) and bids were a few dozen cents. The meta-analysis finds signs of publication bias; adjusted, it is about d = 0.38 (Pelled, 2023, dissertation).
Mochon, Norton and Ariely (2012) have supporting evidence. But Sarstedt et al. (2017) point to ownership, and Marsh et al. (2018) argue ownership is not enough. The mechanism is still debated.
Experiment 3 found that liking DIY did not change the effect, but with only 39 people (Norton et al., 2012). Plausible, needs more data.
Marsh, Kanngiesser and Hood (2018) found it in 5-year-olds. One paper, three studies; it needs replication by other teams.
The classic Harwood clothing factory study (Coch and French, 1948) found that groups that took part in planning new methods adapted faster. It fits the IKEA effect, but it is an old study with a simple design that did not measure the IKEA effect directly.
A story often used to open talks on the IKEA effect. Food historian Laura Shapiro (2004) argues the role of the "egg trick" in cake mix's success is unclear, and fresh eggs may simply have made better cakes (paraphrase, not a direct quote). No experiment ever tested it.
The effect disappears when people fail or do not finish (Norton et al., 2012). In 5- and 6-year-olds, more effort did not strengthen the effect (Marsh et al., 2018). The condition is finishing, not suffering.
A real, moderate effect with a clear condition: you have to finish. Use it so your team owns the result, and remember it is fooling you too.
Dan Ariely, one of the three authors, is a well-known behavioural economist who has also faced data questions. A 2012 study on signing before reporting, which he co-authored, was retracted by PNAS in 2021 because of problems with its data (Shu et al., 2012).
The IKEA effect is not part of the retracted study. More importantly, it has been replicated by unrelated teams (Sarstedt et al., 2017; Marsh et al., 2018) and pooled in a meta-analysis. So Mark trusts the effect because of the replications, not because of who first reported it.
The name "IKEA effect" is just the authors' memorable label, after self-assembled furniture. This piece is not linked to or sponsored by any company.
Work skill: let your team build part of it so they own the result, and do not fall for your own "baby".
Every number in this piece, the Facebook carousel and the captions comes from the studies below.