P13 Data entry

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Information about where the data you use are acquired from is one of the most important things you can record whilst constructing and using a GIS. GIS Guide to Good Practice

References:


 * Data Documentation and Metadata

Primary data
Primary, or 'raw', geospatial data has not been significantly processed or trasformed since the information was first captured. [...] Raw data may also be available from databases of information compiled by other agencies [...]. Primary data may also be extracted from remote sensing sources [...]. CONOLLY J., LAKE M. (2006). Geographical Information Systems in Archaeology. Cambridge


 * Total Station points (since 2010):

Device: Topcon GPT-3107NW; Projection system: Floated; Co-ordinate system: Cartesian (x,y,z); Data type: Points; Precision: 0.001m
 * Records plan maps:

Records (bones, stones, silex) are drawn on a millimetric graph paper from an azimuth point of view. Scale: 1:10; Colors: Yellow (bones), Red (stones), Blue (silex)


 * Records reports:

Records (bones, stones, silex) variables are recorded on an index paper:

Data: Date of discovery in dd/mm/yyyy format;

Codice: Unique ID codex (US + Q + N);

US: Stratigraphic unit (A, B, C, D) and artificial cut (natural number);

Q: 1x1m square;

N: Incremental number of record with prefix (S for bones and silex, P for stones);

Descrizione: Description of record (OSSO, PIETRA, SELCE, DENTE);

(x,y,z are copied from the Total Station);

O: orientation (N/S, NE/SW, E/W, NW/SE);

P: inclination (N, NE, E, SE, S, SW, W,	NW or P, VL, Vl, Vs)

L: length; l: width; s: thickness (major, median and minor axys) in mm;

OSS: observations about the record;


 * Records photos:

Device: Canon EOS 350D DIGITAL + Canon EFS 18-55mm; Compression: JPEG; Naming system: Record ID


 * Taphonomical analysis spreadsheets:


 * Lithic Tecnological analysis spreadsheet:


 * Lithic Functional analysis spreadsheet:

Secondary data
The transfer of data from an existing storage medium (e.g. from paper maps) remains a common route of spatial data acquisition. Secondary data, whether digital or analogue, have by definition already undergone processing and interpretation and their use therefore should come with an understanding of the potential sources of error in the data. CONOLLY J., LAKE M. (2006). Geographical Information Systems in Archaeology. Cambridge


 * Scanned plan maps:

Method: Flatbed color image optical scan

Scanner:

Width x Height: 2481x3508 pixels; Resolution: 300ppi; Compression: JPEG; Color space: sRGB


 * AutoCAD files:

Method: Heads-up digitization of scanned plan maps;

File format: .dwg


 * Records spreadsheet:

Method: Digitization of records reports;

Data quality
[...] we need to pay some attention to the nature of data quality, and to the ways in which it can be controlled and expressed. WHEATLEY D., GILLINGS M. (2002). Spatial technology and archeology. The archaeological applications of GIS, Taylor and Francis, Londra


 * Currency and source


 * Measurement and observation errors


 * Transcription errors

Coding system
With categorical variables it is necessary to represent the values of the categories in a standardized way by using a coding system. It is common in statistical analysis to use a numeric coding system, in fact, using letters rather than numbers can cause problems with some statistical software. FLETCHER M., LOCK G.R. (2005). Digging numbers. Elementary statistics for archaeologists. Oxford University School of Archaeology, Oxford


 * Records table
 * codice: ID key;
 * q: Square;
 * us: Stratigraphic unit;
 * taglio: Artificial cut;
 * n: Record number;
 * descrizione: Description;
 * o: Orientation; Missing value: NA;
 * p: Inclination: N, NE, E, SE, S, SW, W, NW or P[plane], VL[vertical by length], Vl[vertical by width], Vs[vertical by thickness]; Missing value: NA;
 * l_max: Length; Constraint: >= l_med; Missing value: NA;
 * l_med: Width; Constraint: >= s_min; Missing value: NA;
 * s_min: Thickness; Missing value: NA;
 * oss: Observations.