Context :

Aims : Understanding how galaxies evolve and assemble their mass across cosmic time is still a fundamental unsolved issue .
To get insight into the various processes of galaxy mass assembly , the Mass Assembly Survey with SINFONI in VVDS ( MASSIV ) aims at probing the kinematical and chemical properties of a significant and representative sample of high-redshift ( 0.9 \leq z \leq 1.8 ) star-forming galaxies .

Methods : This paper presents the selection function , the observing strategy and the global properties of the MASSIV sample .
This sample contains 84 star-forming galaxies , selected from the VIMOS VLT Deep Survey ( VVDS ) and observed with the SINFONI integral-field spectrograph at the VLT .
We present the redshift distribution , and derive the stellar masses and SED-based star formation rates ( SFR ) .
Integrated metallicities and the presence of type-2 AGNs are investigated using composite 1D spectra built from VIMOS and SINFONI observations .

Results : The MASSIV selection function , based on star formation criteria ( [ O ii ] \lambda 3727Â emission-line strength up to z \sim 1.5 and colors/UV absorption lines at higher redshifts ) , provides a good representation of “ normal ” star-forming galaxies with SED-based SFRs between 5 and 400 M _ { \odot } yr ^ { -1 } Â in the stellar mass regime 10 ^ { 9 } -10 ^ { 11 } M _ { \odot } .
Analysis of typical emission-line ratios performed on composite spectra reveals that the contamination by type-2 AGNs is very low and that the integrated metallicity of the galaxies follows the well-known mass-metallicity relation .

Conclusions : The MASSIV sample has been built upon a simple selection function , fully representative of the star-forming galaxy population at 0.9 < z < 1.8 for SFR \geq 5 M _ { \odot } yr ^ { -1 } .
Together with the size of the sample , the spatially-resolved SINFONI data therefore enables us to discuss global , volume averaged , galaxy kinematic and chemical properties all accross the mass and SFR range of the survey to derive robust conclusions on galaxy mass assembly over cosmological timescales .
All the data published in this paper are publicly available at the time of publication following this link : http : //cosmosdb.lambrate.inaf.it/VVDS-SINFONI .