<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-01-28</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000726603</issuerCik>
        <issuerName>QUESTAR ASSESSMENT, INC.</issuerName>
        <issuerTradingSymbol>QUSA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001228070</rptOwnerCik>
            <rptOwnerName>STRALEY LINDA G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O QUESTAR ASSESSMENT, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>4 HARDSCRABBLE HEIGHTS, P.O. BOX 382</rptOwnerStreet2>
            <rptOwnerCity>BREWSTER</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10509</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Sr. Vice President &amp; Secretary</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $.0001 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2008-01-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4420</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>75727</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Common Stock, Right to Buy</value>
                <footnoteId id="F2"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.5</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2008-01-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2018-01-28</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Shares granted as stock bonus payment pursuant to the 2007 Stock Incentive Plan.</footnote>
        <footnote id="F2">Granted pursuant to the 2007 Stock Incentive Plan.</footnote>
        <footnote id="F3">The options vest in three equal annual installments, commencing January 28, 2009.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Linda G. Straley</signatureName>
        <signatureDate>2008-01-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0202
4
2008-01-28
0
0000726603
QUESTAR ASSESSMENT, INC.
QUSA
0001228070
STRALEY LINDA G
C/O QUESTAR ASSESSMENT, INC.
4 HARDSCRABBLE HEIGHTS, P.O. BOX 382
BREWSTER
NY
10509
0
1
0
0
Sr. Vice President & Secretary
Common Stock, par value $.0001 per share
2008-01-28
4
A
0
4420
0
A
75727
D
Common Stock, Right to Buy
4.5
2008-01-28
4
A
0
5000
0
A
2018-01-28
Common Stock
5000
5000
D
Shares granted as stock bonus payment pursuant to the 2007 Stock Incentive Plan.
Granted pursuant to the 2007 Stock Incentive Plan.
The options vest in three equal annual installments, commencing January 28, 2009.
Linda G. Straley
2008-01-30