Af-d 2/3 n umya

Fren yiwen n umḍan. Ad yerbeḥ win iqerben ɣer 2/3 n umya n yimḍanen n medden deg ddurt-a. Baṭel, war asekkles.

Sɣur tarbaɛt n HelibrainIɛawed-as asenqed Robert(Taglizt), anelmad n doctorate deg biophysiqueYeffeɣ-d Asenqed aneggaru n

Amek ara teɣreḍ agmuḍ-ik

  • Aswir-ik yeskan-d acḥal n tikkal i tesmektiḍ ɣef wayen ara xedmen wiyaḍ. Ma yella afran-ik iqreb ɣer 50, d aswir 0: ur tesmektiḍ ara ɣef wiyaḍ. Ma iqreb ɣer 33, d aswir 1: «medden ad fernen ɣer 50». Ma iqreb ɣer 22, d aswir 2: «medden ad smecktin yiwet n tikkelt sdat». Yal asurif d 2/3 n win i t-id-yezrin [1].
  • Tiririt n tɣuri n uraren d 0. Ma yella yal yiwen yemmeslay alamma yekfa, yal afran ad yeẓẓi ar 0. Imuraren n tilawt ur ttaweḍen ara ɣer waya, ihi 0 ur yerkib ara deg yiwen n umseḍfer azayez [1][2].
  • Ur yezmir ara ad yerbeḥ: afran ameqqran ɣef 66,7 ur yezmir ara ad yerbeḥ, acku xas ma fernen medden akk 100, aswiḍ ad yili 66,7.
  • Win yerbeḥ n ddurt-a ad d-yettban mi ara tfak tɣawsa (yal tɣawsa d ddurt, seg ltnin alama d lḥedd, UTC). Ur d-nesskan ara umya n medden send aya: ad yefsex urar. Iwakken ad yili ugmuḍ, ilaq ad ilin ɣars 30 n yimuraren akka tura.

Anwa n umḍan yelhan ara tferneḍ?

Ulac yiwen n umḍan i yelhan yal tikkelt: yeqqen ɣer wayen fernen wiyaḍ. Deg yimeṣḍaren izayazen n medden, aswiḍ yella gar 13 d 22 s wakal. Iɣerdayen n Financial Times sɛan umya 18,9, ihi aswiḍ yella d 12,6 [2]. Deg umseḍfer n teɣzet tazayezit n Denmark, anda llan 19 196 n yimeɣriyen, umya yella d 32,4; aswiḍ d 21,6 [3].

Aseɣru n yibars: umya n ufran d uswiḍ deg kraḍ n yimseḍfer yettwassnen. Tazrawt n ulaboratu 1995: umya 36.7, aswiḍ 24.5. Politiken 2005: umya 32.4, aswiḍ 21.6. Spektrum 1997: umya 22.1, aswiḍ 14.7. Financial Times 1997: umya 18.9, aswiḍ 12.6.
Tugna 1. Umya n ufran d uswiḍ n 2/3 deg kraḍ n yimseḍfer yettwassnen. Isefka: Nagel 1995, turda tamezwarut, 67 n yiselmaden [1]; Politiken 2005, 19,196 n yimeɣriyen [3]; Spektrum der Wissenschaft 1997, 2,728 n yimeɣriyen, d Financial Times 1997, 1,476 n yimeɣriyen [2].

Bder asebter-a d aɣbalu: Af-d 2/3 n umya. Helibrain. 2026. https://helibrain.com/kab/guess-two-thirds-of-the-average. CC BY 4.0.

Iseɣẓanen ɣef tɣawsa

  • Acu i d-teskan: acḥal n yisurifen sdat i temmeslayeḍ ɣef wayen ara xedmen wiyaḍ. Imusnawen n tedrimt semman-as asentel-a level-k [1][4].
  • Asesteb aqbur: deg turda tamezwarut n tezrawt n Rosemarie Nagel deg 1995, iselmaden fernen deg umya 36,7, ugar n yifranen n medden llan ɣer 33 d 22 [1].
  • Imseḍfer imeqqranen: 1 476 n yimeɣriyen n Financial Times sɛan umya 18,9 (afran yerbeḥ d 13), ma d 19 196 n yimeɣriyen n Politiken sɛan umya 32,4 [2][3].
  • Aṭṭan n 33: deg lqem n New York Times n 2015, anda llan azal n 56,000 n yimeɣriyen, 33 d afran i d-yettwafren s waṭas [5].
  • Anida i d-tekka tmuɣli: amussnaw n tedrimt John Maynard Keynes yessemlal amḍiq n uzniq d tmeɣra n tewriqt, anda ad terbeḥ ma tferneḍ udem ara fernen wiyaḍ [6].

Amek i yetteddu urar-a

  1. Fren yiwen n umḍan ummid seg 0 ar 100, sakin sersen-it.
  2. Afrah n medden akk n ddurt-a yettwaḥseb umya-s mi ara tfak tɣawsa, sakin aswiḍ d 2/3 n umya-nni.
  3. Afram iqerben ad yerbeḥ. Ma mṣadan ifranen, ad bḍun tarbeḥt. Deg ltnin, asebter ad yesken imuraren n ddurt iɛeddan, umya, aswiḍ, afran yerbeḥ, d wamek i d-yettwafren yal umḍan.

Yiwen kan n ufran n yal amdan i yettwaḥsaben deg yal tɣawsa. Nḥesb yiwen n ufran i yal iminig d yiwen i yal tuqqna n internet, ihi imdanen i yesseqdacen yiwen n uẓeṭṭa (aɣerbaz, axxam n twuri, tawacult) ad ttwaḥesben yiwet n tikkelt deg ddurt. Afran wis sin ur yettwaḥseb ara. Mi tferneḍ, asebter ad yesken anda i yella umḍan-ik deg uḍris n umesmekti, d wamek ara yili ugmuḍ-ines deg yimseḍfer iqburen nni.

D acu i yeskan urar-a, d anida i d-yekka

Imusnawen n tedrimt semman-as urar-a p-beauty contest, dagi p = 2/3. Rosemarie Nagel teǧǧa-t d asesteb n ulaboratu yettwassnen deg 1995 [1]. Ayen i d-tebder: imdanen ur ttaweḍen ara alamma d 0 deg umesmekti, daɣen ur tfernen ara s tɣawla. Tuget n medden ḥebsen deffir yiwen neɣ sin n yisurifen n «nettxemmim d acu i yettxemmim wiyaḍ belli nekki txemmimeɣ».

Tamuɣli-a, belli imdanen ttxemmimen s kra n yisurifen kan ɣef wiyaḍ, tettwaɛawed tewwi-d ɣer yimudelen level-k d cognitive hierarchy n umesmekti n tɣawsiwin n tedrimt [4][7]. Imseḍfer n teɣzet i d-yellan deffir waya, s yimeɣriyen iɛeṭṭlen, skan-d isurifen yiwen-nni ɣer 33 d 22, akked ugraw i yefren 0 neɣ 1 [2].

Acu i izmer ad d-yini urar-a, d acu ur izmir ara ad d-yini

Aswir-ik yemmal-d yiwen n ufran deg yiwen n urar. Mačči d aselken n tɣuri n uqerruy, daɣen aswir ameqqran ur yif ara: ad yerbeḥ win i d-yemmalen akken iwata afrah n medden, u medden s umata ḥebsen deg yiwen neɣ sin n yisurifen. Afran n uswir 4 d amesmekti iṣeḥḥan, maca s umata ad yekfu ddaw n uswiḍ.

Imuraren dagi d wid i d-yettasen deg ddurt-nni, mačči d agraw i yeqqimen, ihi aswiḍ ibeddel seg ddurt ɣer tayeḍ. Imseḍfer imeẓẓyanen llan-d s yilugan yemgaraden cwiṭ: Financial Times yessegzaḍ imḍanen ummiden kan, ma Politiken d Spektrum qeblen imḍanen s userḍel [2][3].

Isteqsiyen i d-yettuɣalen s waṭas

D acu i d tiririt i ufran n 2/3 n umya?

Af-d 2/3 n umya ur yesɛi ara tiririt i yeqqimen. Tɣuri n uraren tenna-d d 0, acku yal amuraren yezmer ad yaf acuɣer ara yefren ddaw n wiyaḍ. Maca imdanen n tilawt ḥebsen deffir yiwen neɣ sin n yisurifen, ihi deg yimseḍfer yettwassnen, afran yerbeḥ yella gar 13 d 21.6 [2][3]. Afran yelhan d 2/3 n wayen tettɣileḍ ara fernen wiyaḍ deg umya.

Acuɣer 0 ur yettnerbaḥ ara?

Zero ad yerbeḥ kan ma yella tuget n medden mesmektiyen alamma d 0. Deg yimseḍfer n tilawt, aṭas fernen 33 neɣ 22, daɣen kra fernen imḍanen imeqqranen, ayen i yettaliyen umya. Deg umseḍfer n Financial Times, umya yella d 18,9 u uswiḍ d 12,6, beɛden aṭas ɣef 0 [2].

D acu i d-yesɛa «amesmekti n uswir 2»?

Amesmekti n uswir 2 yettɣil medden ad mesmektiyen sdat s yiwen n usurif (ad fernen ɣer 33), sakin ad yernu yiwen n usurif sdat: 2/3 n 33 d azal n 22. Deg urar n Helibrain, aswir-ik d asurif deg uḍris (50, 33, 22, 15, 10) i iqerben ugar ɣer ufran-ik [1].

Zemreɣ ad urareɣ ugar n yiwet n tikkelt?

Ih, maca afran-ik amezwaru kan n yal ddurt i yettwaḥsaben deg tɣawsa. Ifranen deffir-s ad d-ttwaseknen deg uḍris, maca ur ttwaḥsaben ara, ihi ulac win ara ibeddlen agmuḍ s ufran n aṭas n tikkal. Tɣawsa tamaynut tebdu yal ltnin.

Urar n Helibrain 2/3, d baṭel s tidet?

Ih. Urar n Helibrain 2/3 d ugmuḍ n yal ddurt d baṭel: war asekkles, war imayl, war axelleṣ. Helibrain tettawi-d idrimen seg usnas-ines, yesɛan amɣar baṭel d yimɣaren yettwaḥelsen; ur ilaq ara ad tesqedceḍ asnas i wakken ad turareḍ.

Isekyaden icudden

Wali akk 43 n yisekyaden n uqerruy ilelliyen

Tebɣiḍ ad tɛerḍeḍ fell-as yal ass? Asnas n Helibrain (s tanglizt akka tura) yesɛa amtan ilelli d yamtanen s lexlaṣ.

Bder asebter-a d aɣbalu: Af-d 2/3 n umya. Helibrain. 2026. https://helibrain.com/kab/guess-two-thirds-of-the-average. CC BY 4.0.

How this test works

This is a weekly strategy game. Pick a whole number from 0 to 100. When the week ends, everyone's guesses are averaged, and the winner is whoever comes closest to two thirds of that average. Right after you guess, you see how many steps ahead of other players your number suggests, and how it would have done in famous contests. Economists first ran this game as a lab experiment in 1995.

Version 1 · Cite this test:

Helibrain (2026). Guess 2/3 of the average, v1. https://helibrain.com/guess-two-thirds-of-the-average/methods

Full method →

Iɣbula

  1. Nagel R (1995). Unraveling in guessing games: an experimental study. American Economic Review 85(5):1313–1326. www.jstor.org/stable/2950991
  2. Bosch-Domènech A, Montalvo JG, Nagel R, Satorra A (2002). One, two, (three), infinity, …: newspaper and lab beauty-contest experiments. American Economic Review 92(5):1687–1701. doi.org/10.1257/000282802762024737 (numbers from the 1999 working paper: econ-papers.upf.edu/papers/438.pdf)
  3. Schou A (2005). Gæt-et-tal konkurrence afslører at vi er irrationelle. Politiken, 22 September 2005. politiken.dk/oekonomi/art5698526
  4. Camerer CF, Ho T-H, Chong J-K (2004). A cognitive hierarchy model of games. Quarterly Journal of Economics 119(3):861–898. doi.org/10.1162/0033553041502225
  5. Quealy K (2015). How readers fared in Upshot's number puzzle. The New York Times, 20 August 2015. www.nytimes.com/2015/08/21/upshot/how-readers-fared-in-upshots-number-puzzle.html
  6. Keynes JM (1936). The General Theory of Employment, Interest and Money, chapter 12. London: Macmillan.
  7. Stahl DO, Wilson PW (1995). On players' models of other players: theory and experimental evidence. Games and Economic Behavior 10(1):218–254. doi.org/10.1006/game.1995.1031

Amek nga tasna-agi: tira sɣur tarbaɛt n Helibrain, seg tezrawin i d-yettwabedren nnig, u yettwasenqed sɣur Robert(Taglizt) (anelmad n doctorate deg biophysique) ass n 4 Nunembeṛ 2026. Ad tt-nesseɣti mi ara bedlen yiɣbula.