"It is difficult to grasp the correlation."
"it is difficult ~" 「〜辛い」
"to grasp ~" 「〜が掴み」"to understand" 「〜分かる」も言えます。
"the correlation" 「相関関係」
"The correlation is difficult to see."
"to see" 「見る」・「見分ける」
"It is difficult to see the correlation just from the results."
「この結果だけでは相関関係が掴み辛い」
オーストラリア 
