Start with the instrument and parcel identifiers
A transfer record describes an instrument or transaction, not necessarily an ordinary sale of one home. Illinois’ PTAX-203 instructions distinguish the property identifiers, instrument type, current and intended use, and consideration. Several PINs can be included in one transaction; a condo, parking space and other related parcel may have separate identifiers.
Sources: IDOR: PTAX-203 instructions
Do not assign a whole-deed amount to every parcel
When one recorded consideration covers multiple parcels, retain that scope. Showing the same amount against each PIN does not mean each parcel individually sold for that amount. Likewise, a zero, nominal or undisclosed amount is not evidence of a normal market price.
Cook County Records keeps Assessor sales and IDOR transfer declarations as separate modules. Read the instrument, date, parcel count and source together before drawing a trend. A change in taxpayer mailing information alone does not establish a new legal owner or a transaction.
Write a careful research conclusion
A useful note identifies what the source actually supports: a recorded transfer, a stated consideration and the parcels linked to it. Then state the unresolved items, such as whether the amount includes other real estate or whether the transaction is suitable as a comparable sale.
Use the recent-sales index to discover candidate records, open the individual property history and follow the source. For title, rights or the legal effect of an instrument, obtain the official recorded document and qualified interpretation. The dataset summary is a discovery aid.