獲取教育大數(shù)據(jù)：基于xAPI規(guī)范對(duì)學(xué)習(xí)經(jīng)歷數(shù)據(jù)的獲取與共享

1、    獲取教育大數(shù)據(jù)基于xapi規(guī)范對(duì)學(xué)習(xí)經(jīng)歷數(shù)據(jù)的獲取與共享    安全性。為了保證數(shù)據(jù)的安全性和個(gè)人隱私，lrs需要設(shè)定身份驗(yàn)證機(jī)制，以保證應(yīng)用或個(gè)人必須通過(guò)驗(yàn)證或得到授權(quán)后才能訪(fǎng)問(wèn)lrs內(nèi)的數(shù)據(jù)。xapi規(guī)范規(guī)定lrs必須支持兩種身份驗(yàn)證機(jī)制：http基礎(chǔ)驗(yàn)證和oauth開(kāi)放授權(quán)。如果使用http基礎(chǔ)驗(yàn)證，應(yīng)用需通過(guò)提交認(rèn)證信息來(lái)讓lrs驗(yàn)證身份。當(dāng)用戶(hù)通過(guò)第三方應(yīng)用在lrs中存取數(shù)據(jù)時(shí)，通常需要獲得oauth授權(quán)。oauth授權(quán)協(xié)議允許用戶(hù)讓第三方應(yīng)用訪(fǎng)問(wèn)該用戶(hù)在某一網(wǎng)站上存儲(chǔ)的私密的資源，而無(wú)需將用戶(hù)名和密碼提供給第三方應(yīng)用。lrs通過(guò)向第三

2、方應(yīng)用發(fā)放令牌、授權(quán)證書(shū)、臨時(shí)證書(shū)等方式進(jìn)行授權(quán)，獲得授權(quán)后的應(yīng)用便可以通過(guò)接口訪(fǎng)問(wèn)權(quán)限作用域中的信息。深度查詢(xún)。由于statement接口只可查詢(xún)statement對(duì)象，而statement對(duì)象并不包含學(xué)習(xí)經(jīng)歷的所有內(nèi)容，其很多屬性是以類(lèi)似“指針”或“引用”的形式存在于statement對(duì)象中，因此，如果需要獲取一條完整的學(xué)習(xí)經(jīng)歷數(shù)據(jù)，通常需要多次的數(shù)據(jù)查詢(xún)，而反復(fù)在lrs中查詢(xún)并不是一種高效的方式，當(dāng)數(shù)據(jù)請(qǐng)求較多時(shí)可能會(huì)導(dǎo)致系統(tǒng)的負(fù)擔(dān)很重。因此，lrs采用深度查詢(xún)的方法，將一條數(shù)據(jù)的statement對(duì)象及其關(guān)聯(lián)對(duì)象全部查詢(xún)并整合完畢后，一次性地將結(jié)果返回給數(shù)據(jù)請(qǐng)求方。數(shù)據(jù)質(zhì)量。作為一種數(shù)

3、據(jù)服務(wù)，lrs需要保證所有數(shù)據(jù)的有效性。lrs會(huì)對(duì)所有輸入的數(shù)據(jù)進(jìn)行約束和校驗(yàn)，主要包括語(yǔ)法、格式化、json的值是否匹配規(guī)范要求等。當(dāng)發(fā)現(xiàn)錯(cuò)誤或不準(zhǔn)確的statement對(duì)象時(shí)，lrs會(huì)對(duì)其進(jìn)行特殊的處理由于statement對(duì)象具有不可變的特性，因此它們不能被刪除，lrs會(huì)將它們置為無(wú)效，并在查詢(xún)時(shí)對(duì)其進(jìn)行過(guò)濾。此外，由于lrs流通的數(shù)據(jù)量較為龐大，因此還需要考慮并發(fā)性的問(wèn)題，以及避免發(fā)生數(shù)據(jù)被覆蓋的情況。四、總結(jié)與展望教育大數(shù)據(jù)的應(yīng)用價(jià)值在于將數(shù)據(jù)用作學(xué)習(xí)分析。xapi作為學(xué)習(xí)經(jīng)歷數(shù)據(jù)收集的規(guī)范，有助于為學(xué)習(xí)分析提供各種粒度的實(shí)時(shí)信息，從而完成對(duì)學(xué)習(xí)經(jīng)歷的實(shí)時(shí)跟蹤。在傳統(tǒng)的在線(xiàn)學(xué)習(xí)模式中

4、，xapi的特性無(wú)法最大程度的發(fā)揮。在移動(dòng)學(xué)習(xí)和泛在學(xué)習(xí)日益普及的大背景下，人們通過(guò)移動(dòng)設(shè)備在網(wǎng)絡(luò)中探索、娛樂(lè)、學(xué)習(xí)已經(jīng)成為常態(tài)，幾乎所有的交互、協(xié)作都可以在移動(dòng)設(shè)備上展開(kāi)，而且人們?cè)谝苿?dòng)設(shè)備及移動(dòng)應(yīng)用中交互的意愿相較于以往也更加強(qiáng)烈，這為xapi采集學(xué)習(xí)活動(dòng)各異的學(xué)習(xí)經(jīng)歷創(chuàng)造了機(jī)會(huì)。在移動(dòng)應(yīng)用及移動(dòng)學(xué)習(xí)有可能為教育大數(shù)據(jù)帶來(lái)豐厚的數(shù)據(jù)積累的背景下，xapi將能夠支持移動(dòng)平臺(tái)的各項(xiàng)功能以創(chuàng)建新類(lèi)型的學(xué)習(xí)經(jīng)歷，兩者的結(jié)合將會(huì)產(chǎn)生增值效應(yīng)。目前國(guó)外已經(jīng)基本完成遵循xapi規(guī)范開(kāi)發(fā)的adb(actionable data book)，并計(jì)劃依次在平臺(tái)端、安卓端、iot端(可穿戴設(shè)備、實(shí)驗(yàn)室設(shè)備、傳感

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