「釋義」

選擇性偏差是指人們常常根據(jù)自己對(duì)特定事件的代表性觀點(diǎn)，來(lái)估計(jì)某些事件發(fā)生的概率。這樣人們可能錯(cuò)誤地相信了“小數(shù)定律”，將一系列的負(fù)相關(guān)歸因于一個(gè)確定的和獨(dú)立分布的隨機(jī)過程，從而出現(xiàn)偏差。

?

「應(yīng)用場(chǎng)景」

你在網(wǎng)上寫過評(píng)價(jià)嗎？如果寫過，當(dāng)時(shí)為什么決定這么做？研究顯示，用戶往往會(huì)因?yàn)橄M(fèi)體驗(yàn)決定是否寫評(píng)價(jià)。有些網(wǎng)站，消費(fèi)者在獲得滿意體驗(yàn)時(shí)，更可能留言評(píng)價(jià)，有些則只在極度滿意和極度不滿的情況下，才會(huì)寫評(píng)價(jià)。無(wú)論哪種情況，都會(huì)因選擇性偏差，影響最終評(píng)分。這樣的評(píng)價(jià)也許無(wú)法準(zhǔn)確展現(xiàn)該產(chǎn)品用戶體驗(yàn)全貌。比如，如果只有對(duì)產(chǎn)品滿意的顧客留下評(píng)價(jià)，產(chǎn)品評(píng)分就會(huì)虛高。如果企業(yè)只鼓勵(lì)滿意的客戶評(píng)價(jià)，選擇性偏差的影響會(huì)更明顯。

Have you ever written an online review? If so, what made you decide to comment on that particular occasion? Research has shown that users’ decisions to leave a review often depend on the quality of their experience. On some sites, customers may be likelier to leave reviews if their experience was good; on others, only if it was very good or very bad. In either case the resulting ratings can suffer from selection bias: They might not accurately represent the full range of customers’ experiences of the product. If only satisfied people leave reviews, for example, ratings will be artificially inflated. Selection bias can become even more pronounced when businesses nudge only happy customers to leave a review.

?

eBay在2011年遭遇過選擇性偏差問題，發(fā)現(xiàn)賣家評(píng)分高得可疑：多數(shù)賣家的好評(píng)率超過99%。公司在經(jīng)濟(jì)學(xué)家克里斯·諾斯克和斯蒂文·泰迪利斯的幫助下，發(fā)現(xiàn)用戶在獲得滿意體驗(yàn)后，更有可能寫評(píng)價(jià)：在網(wǎng)站已完成的約4400萬(wàn)項(xiàng)交易中，只有0.39%獲得差評(píng)或負(fù)分，但實(shí)際出現(xiàn)“爭(zhēng)端”的人有兩倍之多（1%），7倍以上（3%）的交易顯示，買家曾聯(lián)系賣家抱怨產(chǎn)品質(zhì)量。實(shí)際上相比賣家得分，買家是否給賣家寫評(píng)價(jià)的決定，能更好預(yù)測(cè)未來(lái)買家是否會(huì)投訴賣家，也能更好體現(xiàn)產(chǎn)品質(zhì)量。

EBay encountered the challenge of selection bias in 2011, when it noticed that its sellers’ scores were suspiciously high: Most sellers on the site had over 99% positive ratings. The company worked with the economists Chris Nosko and Steven Tadelis and found that users were much likelier to leave a review after a good experience: Of some 44 million transactions that had been completed on the site, only 0.39% had negative reviews or ratings, but more than twice as many (1%) had an actual “dispute ticket,” and more than seven times as many (3%) had prompted buyers to exchange messages with sellers that implied a bad experience. Whether or not buyers decided to review a seller was in fact a better predictor of future complaints—and thus a better proxy for quality—than that seller’s rating.

以上文字選自《哈佛商業(yè)評(píng)論》中文版2019年12月刊《設(shè)計(jì)更優(yōu)化的網(wǎng)絡(luò)評(píng)價(jià)體系》

杰夫·唐納克（GeoffDonaker）金炫進(jìn)（Hyunjin Kim）邁克爾·盧卡（Michael Luca）丨文

馬冰侖?丨編輯?